mb/google/nissa/var/joxer: support for different WiFi SAR tables

Set the WIFI_SAR_ID field in FW_CONFIG to selcet the correct SAR table.

BUG=b:285477026
TEST=emerge-nissa coreboot and check the SAR value

Signed-off-by: Mark Hsieh <mark_hsieh@wistron.corp-partner.google.com>
Change-Id: Ibea62c77ecad9b2c475452b706779e4cfc6b06d4
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76144
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Derek Huang <derekhuang@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

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

@@ -1,3 +1,10 @@
+fw_config
+	field WIFI_SAR_ID 6 6
+		option WIFI_GFP2_SAR_ID_0	0
+		option WIFI_GFP2_SAR_ID_1	1
+		end
+end
+
 chip soc/intel/alderlake
 	register "sagv" = "SaGv_Enabled"
 

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

@@ -9,7 +9,7 @@
 
 const char *get_wifi_sar_cbfs_filename(void)
 {
-	return "wifi_sar_0.hex";
+	return get_wifi_sar_fw_config_filename(FW_CONFIG_FIELD(WIFI_SAR_ID));
 }
 
 void variant_devtree_update(void)