package/spirv-headers: add patch to fix build with spirv-llvm-translator >= 22.1.3

The upcoming bump of spirv-llvm-translator to 22.1.3 includes upstream
commit
https://github.com/KhronosGroup/SPIRV-LLVM-Translator/commit/5a8baf6cd2b573fa40ed8e6c5e3eedadbe0c76e7

which depends on an upstream patch to spirv-headers:
https://github.com/KhronosGroup/SPIRV-Headers/commit/b8a32968473ce852a809b9de5f04f02a5a9dfa78

according to
https://github.com/KhronosGroup/SPIRV-LLVM-Translator/pull/3721

but this patch is not included in any release of spirv-headers yet so we
need to add it to buildroot to prevent a build error with
spirv-llvm-translator 22.1.3.

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Julien Olivain <ju.o@free.fr>