mb/gigabyte/ga-b75m-d3v: add libgfxinit support

On this device libgfxinit successfully initializes textmode and 
framebuffer mode on the device connected to the HDMI1 port.

VGA port is not tested, due to lack of VGA with valid EDID.

Every ports works on GNU/Linux with kernel version 4.9+80+deb9u1.

Due to limitations within the libgfxinit's current build system,
it needs "select NORTHBRIDGE_INTEL_IVYBRIDGE" to work, even it is
PCH instead of CPU for which libgfxinit should be configured here.

Change-Id: Ib1513fc57b79eebc5d047c2e24585731c44bc215
Signed-off-by: Bill XIE <persmule@gmail.com>
Reviewed-on: https://review.coreboot.org/21071
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

src/mainboard/gigabyte/ga-b75m-d3v/Kconfig

@@ -4,7 +4,7 @@ config BOARD_SPECIFIC_OPTIONS
 	def_bool y
 	select ARCH_X86
 	select CPU_INTEL_SOCKET_LGA1155
-	select NORTHBRIDGE_INTEL_SANDYBRIDGE
+	select NORTHBRIDGE_INTEL_IVYBRIDGE
 	select USE_NATIVE_RAMINIT
 	select SOUTHBRIDGE_INTEL_C216
 	select SUPERIO_ITE_IT8728F
@@ -16,6 +16,7 @@ config BOARD_SPECIFIC_OPTIONS
 	select HAVE_SMI_HANDLER
 	select INTEL_INT15
 	select SERIRQ_CONTINUOUS_MODE
+	select MAINBOARD_HAS_LIBGFXINIT
 
 config DRAM_RESET_GATE_GPIO
 	int

src/mainboard/gigabyte/ga-b75m-d3v/Makefile.inc

@@ -14,3 +14,4 @@
 ##
 
 romstage-y += gpio.c
+ramstage-$(CONFIG_MAINBOARD_USE_LIBGFXINIT) += gma-mainboard.ads

src/mainboard/gigabyte/ga-b75m-d3v/gma-mainboard.ads

@@ -0,0 +1,28 @@
+--
+-- Copyright (C) 2017 Bill XIE persmule@gmail.com
+--
+-- 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 :=
+     (HDMI1,
+      Analog,
+      others => Disabled);
+
+end GMA.Mainboard;