sched/init/nx_start.c: Add support for CONFIG_BOARD_DRIVER_INITIALIZE. If this option is selected then nx_start() will call a board-provided function board_driver_initialize() immediately after calling up_initialize().
Rename CONFIG_BOARD_INITIALIZE to CONFIG_BOARD_LATE_INITIALIZE.
Raname board_initialize() to board_late_initialize()
Squashed commit of the following:
configs/*/README.txt: Replace each occurrence of './configure.sh' with 'tools/configure.sh'
configs/*/README.txt: Remove 'cd ..' after each './configure.sh'
configs/*/README.txt: Remove 'cd -' after each './configure.sh'
configs/*/README.txt: Remove 'cd tools' before each './configure.sh'
configs/README.txt: Remove instruction to CD tools/ before running configure.sh.