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>
Add a minimal implementation to suppress warnings when building
application code shared with other operating systems.
For example:
When building with a c++ compiler and GCC 12.2.0, the following warning is emitted:
nuttx/include/spawn.h:178:40: warning: statement has no effect [-Wunused-value]
178 | #define posix_spawnattr_destroy(attr) (0)