drivers/intel/gma: Guard add_vbt_to_cbfs macro

Guard macro via CONFIG_INTEL_GMA_ADD_VBT, rather than guarding
each of the calls to it (most of which are currently unguarded).

Test: build google/coral w/ and w/o CONFIG_INTEL_GMA_ADD_VBT selected,
verify VBTs added (or not) to CBFS based on Kconfig selection.

Change-Id: Ic25554cb2c61b81bdb4b0987094c3558e0bbcbd8
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61768
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/src/drivers/intel/gma/Makefile.inc b/src/drivers/intel/gma/Makefile.inc
index 964d13e..5588e5a 100644
--- a/src/drivers/intel/gma/Makefile.inc
+++ b/src/drivers/intel/gma/Makefile.inc
@@ -8,6 +8,7 @@
 ramstage-$(CONFIG_INTEL_GMA_ACPI) += acpi.c
 ramstage-$(CONFIG_INTEL_GMA_ACPI) += opregion.c
 
+ifeq ($(CONFIG_INTEL_GMA_ADD_VBT),y)
 # add_vbt_to_cbfs, first argument is the filename in cbfs, the second one
 # is the filename in the coreboot tree.
 add_vbt_to_cbfs= \
@@ -15,11 +16,10 @@
 	$(eval $1-file := $2) \
 	$(eval $1-type := raw) \
 	$(eval $1-compression := lzma)
-
-ifeq ($(CONFIG_INTEL_GMA_ADD_VBT),y)
-$(call add_vbt_to_cbfs, vbt.bin, $(call strip_quotes,$(CONFIG_INTEL_GMA_VBT_FILE)))
 endif
 
+$(call add_vbt_to_cbfs, vbt.bin, $(call strip_quotes,$(CONFIG_INTEL_GMA_VBT_FILE)))
+
 ifeq ($(CONFIG_GFX_GMA),y)
 
 $(call add-special-class,gfxinit)