mb/siemens/mc_apl7: Enable libgfxinit for the board

Add the gma-mainboard.ads for display output definition and enable the
libgfxinit usage in mainboard Kconfig.

Change-Id: I7e7a44736a8136b5320821e744134c7d64c7f1b4
Signed-off-by: Jan Samek <jan.samek@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67683
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/siemens/mc_apl1/variants/mc_apl7/Kconfig

@@ -7,6 +7,7 @@ config BOARD_SPECIFIC_OPTIONS
 	select SOC_INTEL_SET_MIN_CLOCK_RATIO
 	select DRIVERS_I2C_PTN3460
 	select PTN3460_EARLY_INIT
+	select MAINBOARD_HAS_LIBGFXINIT
 
 config UART_FOR_CONSOLE
 	default 1

src/mainboard/siemens/mc_apl1/variants/mc_apl7/Makefile.inc

@@ -4,3 +4,4 @@ romstage-y += memory.c
 
 ramstage-y += gpio.c
 ramstage-y += lcd_panel.c
+ramstage-$(CONFIG_MAINBOARD_USE_LIBGFXINIT) += gma-mainboard.ads

src/mainboard/siemens/mc_apl1/variants/mc_apl7/gma-mainboard.ads

@@ -0,0 +1,15 @@
+-- SPDX-License-Identifier: GPL-2.0-or-later
+
+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 :=
+     (eDP,
+      others => Disabled);
+
+end GMA.Mainboard;