mb/purism/librem_mini: Add libgfxinit support

Tested on Librem Mini v1 (WHL), both DisplayPort and HDMI 2.0 work.

Change-Id: I0da26fef304583eec0375eee2082a9d2ebe27292
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46627
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>

src/mainboard/purism/librem_cnl/Kconfig

@@ -6,6 +6,7 @@ config BOARD_PURISM_BASEBOARD_LIBREM_CNL
 	select HAVE_ACPI_RESUME
 	select HAVE_ACPI_TABLES
 	select INTEL_GMA_HAVE_VBT
+	select MAINBOARD_HAS_LIBGFXINIT
 	select NO_UART_ON_SUPERIO
 	select SOC_INTEL_COMMON_BLOCK_HDA_VERB
 	select SPD_CACHE_IN_FMAP

src/mainboard/purism/librem_cnl/Kconfig.name

@@ -13,7 +13,6 @@ config BOARD_PURISM_LIBREM_14
 	select BOARD_PURISM_BASEBOARD_LIBREM_CNL
 	select DRIVERS_I2C_HID
 	select EC_LIBREM_EC
-	select MAINBOARD_HAS_LIBGFXINIT
 	select MAINBOARD_HAS_LPC_TPM
 	select MAINBOARD_HAS_TPM1
 	select SOC_INTEL_COMETLAKE_1

src/mainboard/purism/librem_cnl/variants/librem_mini/gma-mainboard.ads

@@ -0,0 +1,16 @@
+-- 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 :=
+     (DP1,  -- DisplayPort connector
+      DP2,  -- HDMI connector through Parade DP175 LSPCON
+      others => Disabled);
+
+end GMA.Mainboard;