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>
update LIBFDT to LIBC_FDT
move version_gen.h and place it under nuttx/libs/libc/fdt/
change include path to nuttx/libs/libc/fdt/dtc/
Signed-off-by: liaoao <liaoao@xiaomi.com>