mb/google/nissa/var/glassway: Enable Wi-Fi sar table for Intel module

1.Enable CHROMEOS_WIFI_SAR flag to load a SAR table for Intel module.

2.Describe the FW_CONFIG probe for the settings on glassway.
- WIFI_SAR_0 for Intel Wi-Fi module AX211

BUG=336051631
BRANCH=firmware-nissa-15217.B
TEST=emerge-nissa coreboot chromeos-bootimage

Change-Id: I9e43081c93ef17291c5d55cf262a0f4d1497447b
Signed-off-by: Daniel_Peng <Daniel_Peng@pegatron.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/81781
Reviewed-by: Daniel Peng <daniel_peng@pegatron.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <ericllai@google.com>

src/mainboard/google/brya/Kconfig

@@ -262,6 +262,7 @@ config BOARD_GOOGLE_GLASSWAY
 	select DRIVERS_GENERIC_GPIO_KEYS
 	select DRIVERS_GENESYSLOGIC_GL9750
 	select EC_GOOGLE_CHROMEEC_INCLUDE_SSFC_IN_FW_CONFIG
+	select CHROMEOS_WIFI_SAR if CHROMEOS
 
 config BOARD_GOOGLE_GOTHRAX
 	select BOARD_GOOGLE_BASEBOARD_NISSA

src/mainboard/google/brya/variants/glassway/Makefile.mk

@@ -4,3 +4,4 @@ bootblock-y += gpio.c
 romstage-y += gpio.c
 
 ramstage-y += gpio.c
+ramstage-y += variant.c

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

@@ -13,6 +13,9 @@ fw_config
 		option SD_ABSENT		 0
 		option SD_GL9750S		 1
 	end
+	field WIFI_SAR_ID 10 12
+		option WIFI_SAR_ID_0		 0
+	end
 	field TOUCHSCREEN_SOURCE 32 33
 		option TOUCHSCREEN_UNPROVISIONED 0
 		option TOUCHSCREEN_ELAN0001      1

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

@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <baseboard/variants.h>
+#include <chip.h>
+#include <fw_config.h>
+#include <sar.h>
+
+const char *get_wifi_sar_cbfs_filename(void)
+{
+	return get_wifi_sar_fw_config_filename(FW_CONFIG_FIELD(WIFI_SAR_ID));
+}