mb/google/brox/var/lotso: Enable wifi sar

wifi.SetTXPower test fail, so enable wifi sar.

BUG=b:351698478
TEST=emerge-brox coreboot

Change-Id: Ibf5425e72eddc45e376ef4e2d077180dab502200
Signed-off-by: Kun Liu <liukun11@huaqin.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83793
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jian Tong <tongjian@huaqin.corp-partner.google.com>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>

src/mainboard/google/brox/Kconfig

@@ -76,6 +76,7 @@ config BOARD_GOOGLE_BROX_EC_ISH
 
 config BOARD_GOOGLE_LOTSO
 	select BOARD_GOOGLE_BASEBOARD_BROX
+	select CHROMEOS_WIFI_SAR if CHROMEOS
 	select USE_UNIFIED_AP_FIRMWARE_FOR_UFS_AND_NON_UFS
 
 config BOARD_GOOGLE_GREENBAYUPOC