mb/google/volteer: Enable EARLY_EC_SYNC

This enables EC software sync in romstage.

BUG=b:148259137
TEST=verified EC is updated in romstage using coreboot serial console
	logs.

Change-Id: Ibb97c1d57220f7fd74131a5aee450b1ab4b1c982
Signed-off-by: Caveh Jalali <caveh@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41078
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/volteer/Kconfig

@@ -30,6 +30,7 @@ config CHROMEOS
 	select HAS_RECOVERY_MRC_CACHE
 	select MRC_CLEAR_NORMAL_CACHE_ON_RECOVERY_RETRAIN
 	select VBOOT_LID_SWITCH
+	select VBOOT_EARLY_EC_SYNC
 
 config DIMM_SPD_SIZE
 	int