[build] gcc: allow specifying CFLAGS for specific targets
[ti cc3200] initial files: stub implementation
[ti cc3200] minimal kconfig
[ti cc3200] cc3200 bsp link and subdir decl.
[ti cc3200] board definition (stub)
[ti cc3200] platform consts link
[ti cc3200] minimal includes for bsp support
[ti cc3200] minimal API support for compilation
[ti cc3200] initial defconfig
[ti cc3200] add to CI