guids.S: Include <cet.h> when CET is enabled
guids.S: Include <cet.h> when CET is enabled

Intel Control-flow Enforcement Technology (CET):

https://software.intel.com/en-us/articles/intel-sdm

contains shadow stack (SHSTK) and indirect branch tracking (IBT). When
CET is enabled, ELF object files must be marked with .note.gnu.property
section. CET enabled GCC provides a header file, <cet.h>, which can be
included in assembly files to generate the CET marker automatically.

Signed-off-by: H.J. Lu <e6b730070cb8ff71eb70dcaf29e26324d883b33b@gmail.com>

vathpela/efivar-devel,rhboot/efivar,rhinstaller/efivar,rhinstaller/efivar,rhboot/efivar