google/auron: hook up libgfxinit

Internal/external displays functional on all variants
other than Samus. Unable to verify external outputs on
Samus (USB-C using DP/HDMI adapter).

Test: build/boot lulu variant with libgfxinit, verify internal/
external displays functional prior to OS display driver loaded.
Both linear framebuffer and scaled VGA text modes functional.

Change-Id: I867b2604861ebae02936e7fc0e7230a6adcb2d20
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36107
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/mainboard/google/auron/Kconfig

@@ -9,6 +9,7 @@ config BOARD_GOOGLE_BASEBOARD_AURON
 	select HAVE_OPTION_TABLE
 	select HAVE_ACPI_RESUME
 	select MAINBOARD_HAS_CHROMEOS
+	select MAINBOARD_HAS_LIBGFXINIT
 	select MAINBOARD_HAS_LPC_TPM
 	select MAINBOARD_HAS_TPM1
 	select INTEL_INT15

src/mainboard/google/auron/Makefile.inc

@@ -35,3 +35,5 @@ subdirs-y += variants/$(VARIANT_DIR)/spd
 CPPFLAGS_common += -I$(src)/mainboard/$(MAINBOARDDIR)/variants/$(VARIANT_DIR)/include
 
 romstage-y += variants/$(VARIANT_DIR)/gpio.c
+
+ramstage-$(CONFIG_MAINBOARD_USE_LIBGFXINIT) += gma-mainboard.ads

src/mainboard/google/auron/gma-mainboard.ads

@@ -0,0 +1,30 @@
+--
+-- This file is part of the coreboot project.
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; either version 2 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+
+with HW.GFX.GMA;
+with HW.GFX.GMA.Display_Probing;
+
+use HW.GFX.GMA;
+use HW.GFX.GMA.Display_Probing;
+
+private package GMA.Mainboard is
+
+   ports : constant Port_List :=
+     (Internal,
+      HDMI1,
+      DP1,
+      DP2,
+      others => Disabled);
+
+end GMA.Mainboard;