mb/google/brya: Change "mainboard: EC init" loglevel prefix

Change loglevel prefix "BIOS_ERR" to "BIOS_DEBUG".

BUG=b:220639445
TEST=emerge-brya coreboot chromeos-bootimage

Signed-off-by: Ian Feng <ian_feng@compal.corp-partner.google.com>
Change-Id: Ie3de63fc13e7a5ed6a4b4617542851782fbb6f00
Reviewed-on: https://review.coreboot.org/c/coreboot/+/62508
Reviewed-by: EricR Lai <ericr_lai@compal.corp-partner.google.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/brya/ec.c

@@ -16,7 +16,7 @@ void mainboard_ec_init(void)
 		.s0ix_wake_events = MAINBOARD_EC_S0IX_WAKE_EVENTS,
 	};
 
-	printk(BIOS_ERR, "mainboard: EC init\n");
+	printk(BIOS_DEBUG, "mainboard: EC init\n");
 
 	google_chromeec_events_init(&info, acpi_is_wakeup_s3());
 }