mb/google/brya/var/kinox: Select VBT based on FW_CONFIG

Select vbt bin files based on DB_DISPLAY field of FW_CONFIG.

BUG=b:233690293
TEST=emerge-brask coreboot

Signed-off-by: Dtrain Hsu <dtrain_hsu@compal.corp-partner.google.com>
Change-Id: Idb92be66927259732bfd27e4db2c9f242da7d200
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63918
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Zhuohao Lee <zhuohao@google.com>

src/mainboard/google/brya/variants/kinox/Makefile.inc

@@ -1,6 +1,9 @@
 # SPDX-License-Identifier: GPL-2.0-only
 bootblock-y += gpio.c
+
 romstage-y += gpio.c
 romstage-y += memory.c
+
 ramstage-y += gpio.c
 ramstage-y += ramstage.c
+ramstage-y += variant.c

src/mainboard/google/brya/variants/kinox/overridetree.cb

@@ -1,3 +1,11 @@
+fw_config
+	field DB_DISPLAY 0 3
+		option DB_ABSENT	0
+		option DB_HDMI		1
+		option DB_DP		2
+	end
+end
+
 chip soc/intel/alderlake
 	# Intel Common SoC Config
 	#+-------------------+---------------------------+

src/mainboard/google/brya/variants/kinox/variant.c

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+#include <drivers/intel/gma/opregion.h>
+#include <fw_config.h>
+
+const char *mainboard_vbt_filename(void)
+{
+	if (fw_config_probe(FW_CONFIG(DB_DISPLAY, DB_HDMI))) {
+		printk(BIOS_INFO, "Use vbt-kinox_HDMI.bin\n");
+		return "vbt-kinox_HDMI.bin";
+	}
+	printk(BIOS_INFO, "Use vbt.bin\n");
+	return "vbt.bin";
+}