Kconfig: Move and rename ADD_VBT_DATA_FILE

Move ADD_VBT_DATA_FILE to "Devices" menu and rename it to
INTEL_GMA_ADD_VBT_DATA_FILE.
Depend on Intel platforms to avoid confusing users of non-Intel platforms.

The Intel GMA driver will use the vbt.bin, if present, to fill the
ACPI OpRegion.

Change-Id: I688bac339c32e9c856642a0f4bd5929beef06409
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/20619
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/src/soc/intel/skylake/Kconfig b/src/soc/intel/skylake/Kconfig
index 4927eac..b045486 100644
--- a/src/soc/intel/skylake/Kconfig
+++ b/src/soc/intel/skylake/Kconfig
@@ -93,7 +93,7 @@
 	def_bool y
 	depends on MAINBOARD_USES_FSP2_0
 	select PLATFORM_USES_FSP2_0
-	select ADD_VBT_DATA_FILE if RUN_FSP_GOP
+	select INTEL_GMA_ADD_VBT_DATA_FILE if RUN_FSP_GOP
 	select POSTCAR_CONSOLE
 	select POSTCAR_STAGE