cpu/intel/microcode: Apply more strict guard for assembly files

Change-Id: I8243be7c9a57402b2ac1cfa1c0552990d4a4ba74
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37891
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/drivers/intel/fsp1_1/Kconfig

@@ -15,6 +15,7 @@ config PLATFORM_USES_FSP1_1
 	bool
 	select UEFI_2_4_BINDING
 	select INTEL_GMA_ADD_VBT if RUN_FSP_GOP
+	select MICROCODE_UPDATE_PRE_RAM
 	help
 	  Does the code require the Intel Firmware Support Package?