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

Add wifi sar for cret.

BUG=b:194163601
TEST=enable CHROMEOS_WIFI_SAR in config of coreboot,
emerge-dedede coreboot-private-files-baseboard-dedede coreboot chromeos-bootimage.

Signed-off-by: Ian Feng <ian_feng@compal.corp-partner.google.com>
Change-Id: Ic2f3dbc5822c1f4b1c935c87295ba9916e0e359e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56474
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

@@ -143,6 +143,7 @@ config BOARD_GOOGLE_CRET
 	select BASEBOARD_DEDEDE_LAPTOP
 	select DRIVERS_GENERIC_MAX98357A
 	select DRIVERS_I2C_DA7219
+	select GEO_SAR_ENABLE if CHROMEOS_WIFI_SAR
 
 config BOARD_GOOGLE_PIRIKA
 	bool "-> Pirika"

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

@@ -1,5 +1,6 @@
 ## SPDX-License-Identifier: GPL-2.0-or-later
 
 ramstage-y += gpio.c
+ramstage-$(CONFIG_FW_CONFIG) += variant.c
 
 smm-y += variant.c

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

@@ -3,7 +3,14 @@
 #include <acpi/acpi.h>
 #include <baseboard/variants.h>
 #include <delay.h>
+#include <fw_config.h>
 #include <gpio.h>
+#include <sar.h>
+
+const char *get_wifi_sar_cbfs_filename(void)
+{
+	return "wifi_sar-cret.hex";
+}
 
 static void power_off_lte_module(void)
 {