LICENSE: add license for libs/libc/machine/sim

document the license for libs/libc/machine/sim

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

LICENSE

@@ -1,4 +1,4 @@
-                                Apache License
+                               Apache License
                            Version 2.0, January 2004
                         http://www.apache.org/licenses/
 
@@ -4415,6 +4415,42 @@ libs/libc/machine/arm/armv8-m
  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+libs/libc/machine/sim/arch_setjmp_arm.S
+==========================================
+
+  Copyright (C) 2017 Gregory Nutt. All rights reserved.
+  Author: Nickolay Semyonov (RPI) <snob@wolpike.com>
+
+Extracted from the MUSL C-library.  The MUSL C library has a compatible
+MIT license and is released here under the NuttX 3-clause BSD license:
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in
+   the documentation and/or other materials provided with the
+   distribution.
+3. Neither the name NuttX nor the names of its contributors may be
+   used to endorse or promote products derived from this software
+   without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
 libs/libc/math/__cos.c
 libs/libc/math/__sin.c
 libs/libc/math/lib_lgamma.c