Add new PCD PcdBootRestrictToFirmware. When set to TRUE restrict boot options to EFI applications embedded into the firmware image. Behavior should be identical to the PlatformBootManagerLibGrub library variant. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Jiewen Yao <Jiewen.yao@intel.com> Acked-by: Ard Biesheuvel <ardb@kernel.org>