cmake: migrate to SPDX identifier

Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>

cmake/menuconfig.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/menuconfig.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_add_application.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_add_application.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_add_dependencies.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_add_dependencies.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_add_library.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_add_library.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_add_module.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_add_module.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_add_romfs.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_add_romfs.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_add_subdirectory.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_add_subdirectory.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_add_symtab.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_add_symtab.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_allsyms.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_allsyms.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_create_symlink.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_create_symlink.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_export_header.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_export_header.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_generate_headers.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_generate_headers.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_generate_outputs.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_generate_outputs.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_kconfig.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_kconfig.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_mkconfig.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_mkconfig.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_mkversion.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_mkversion.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_parse_function_args.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_parse_function_args.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_redefine_symbols.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_redefine_symbols.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_sethost.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_sethost.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/nuttx_source_file_properties.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/nuttx_source_file_properties.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/savedefconfig.cmake

@@ -1,6 +1,8 @@
 # ##############################################################################
 # cmake/savedefconfig.cmake
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 # Licensed to the Apache Software Foundation (ASF) under one or more contributor
 # license agreements.  See the NOTICE file distributed with this work for
 # additional information regarding copyright ownership.  The ASF licenses this

cmake/symtab.c.in

@@ -1,6 +1,8 @@
 /****************************************************************************
  * cmake/symtab.c.in
  *
+ * SPDX-License-Identifier: Apache-2.0
+ *
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.  The