mb/google/nissa/var/craask: Add wifi sar table

Add wifi sar table for craask/craaskbowl.
Use fw_config to separate different project settings.

BUG=b:247652032,b:251287099,b:251287101
Test=emerge-nissa coreboot

Signed-off-by: Tyler Wang <tyler.wang@quanta.corp-partner.google.com>
Change-Id: I5c92f0ab53ece12a97068f09241e5298909116aa
Reviewed-on: https://review.coreboot.org/c/coreboot/+/68660
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Reka Norman <rekanorman@chromium.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>

src/mainboard/google/brya/Kconfig.name

@@ -226,6 +226,7 @@ config BOARD_GOOGLE_CRAASK
 	select DRIVERS_GENESYSLOGIC_GL9750
 	select DRIVERS_INTEL_MIPI_CAMERA
 	select HAVE_WWAN_POWER_SEQUENCE
+	select CHROMEOS_WIFI_SAR if CHROMEOS
 
 config BOARD_GOOGLE_OSIRIS
 	bool "->  Osiris"

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

@@ -4,4 +4,5 @@ bootblock-y += gpio.c
 romstage-y += gpio.c
 
 ramstage-$(CONFIG_FW_CONFIG) += fw_config.c
+ramstage-$(CONFIG_FW_CONFIG) += variant.c
 ramstage-y += gpio.c

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

@@ -20,6 +20,10 @@ fw_config
 	field AMP 6 7
 		option AMP_MX98360A		0
 	end
+	field WIFI_SAR_ID 13 15
+		option ID_0			0
+		option UNUSED			7
+	end
 	field CODEC 32 33
 		option CODEC_ALC5682I_VS	0
 		option CODEC_NAU8825		1

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

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+#include <fw_config.h>
+#include <sar.h>
+
+const char *get_wifi_sar_cbfs_filename(void)
+{
+	if (fw_config_probe(FW_CONFIG(WIFI_SAR_ID, ID_0))) {
+		printk(BIOS_INFO, "Use wifi_sar_0.hex.\n");
+		return "wifi_sar_0.hex";
+	}
+
+	else if (fw_config_probe(FW_CONFIG(WIFI_SAR_ID, UNUSED))) {
+		printk(BIOS_INFO, "Wi-Fi SAR not used, return NULL!\n");
+	}
+
+	return NULL;
+}