Fix build with gnu-efi 3.0.4
Fix build with gnu-efi 3.0.4

Without efiprot.h the build fails with the following error:

    In file included from apple_set_os.c:7:0:
    /usr/include/efi/efiapi.h:828:5: error: unknown type name ‘EFI_IMAGE_UNLOAD’
         EFI_IMAGE_UNLOAD                UnloadImage;
         ^~~~~~~~~~~~~~~~

0xbb/apple_set_os.efi