mb/google/dedede/var/madoo: Add Wifi SAR for madoo

Add wifi sar for madoo.
Using tablet mode of fw config to decide to load custom wifi sar or not.

BUG=b:165105210
TEST=enable CHROMEOS_WIFI_SAR in config of coreboot,
emerge-dedede coreboot-private-files-baseboard-dedede coreboot chromeos-bootimage.

Signed-off-by: Dtrain Hsu <dtrain_hsu@compal.corp-partner.google.com>
Change-Id: Ic6128b966c952cdc02a6359c14fa41f22265039a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45439
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: EricR Lai <ericr_lai@compal.corp-partner.google.com>

src/mainboard/google/dedede/Kconfig.name

@@ -34,6 +34,7 @@ config BOARD_GOOGLE_MADOO
 	select BOARD_GOOGLE_BASEBOARD_DEDEDE
 	select BASEBOARD_DEDEDE_LAPTOP
 	select DRIVERS_GENERIC_MAX98357A
+	select GEO_SAR_ENABLE if CHROMEOS_WIFI_SAR
 
 config BOARD_GOOGLE_WADDLEDOO
 	bool "Waddledoo"

src/mainboard/google/dedede/variants/madoo/Makefile.inc

@@ -1,3 +1,4 @@
 ## SPDX-License-Identifier: GPL-2.0-or-later
 
 ramstage-y += gpio.c
+ramstage-$(CONFIG_FW_CONFIG) += variant.c

src/mainboard/google/dedede/variants/madoo/variant.c

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <fw_config.h>
+#include <sar.h>
+
+const char *get_wifi_sar_cbfs_filename(void)
+{
+	const char *filename = NULL;
+
+	if (fw_config_probe(FW_CONFIG(TABLETMODE, TABLETMODE_ENABLED)))
+		filename = "wifi_sar-madoo.hex";
+
+	return filename;
+}