soc/intel/common: Move gfx.asl to drivers/intel/gma

Adjust platform-level includes as needed.

Change-Id: I376349ccddb95c166f0836ec1273bb8252c7c155
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48959
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>

src/drivers/intel/gma/acpi/gfx.asl

@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+Device (GFX0)
+{
+	Name (_ADR, 0x00020000)
+}