drivers/intel/gma: Unify VBT related Kconfig names

Shuffle words and drop the _DATA_FILE suffix.

Change-Id: I0b0d50ea729e5580c0bc7b43f250ff387ce59cfc
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/26898
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/soc/intel/skylake/graphics.c

@@ -101,7 +101,7 @@ uintptr_t graphics_soc_write_acpi_opregion(struct device *device,
 	global_nvs_t *gnvs = cbmem_find(CBMEM_ID_ACPI_GNVS);
 
 	/* If GOP is not used, exit here */
-	if (!IS_ENABLED(CONFIG_INTEL_GMA_ADD_VBT_DATA_FILE))
+	if (!IS_ENABLED(CONFIG_INTEL_GMA_ADD_VBT))
 		return current;
 
 	/* If IGD is disabled, exit here */