libpayload: Use usb_debug() to show USB messages

Previously printf()'s were used to show USB messages
which results in lots of USB information being shown
when it isn't needed. This will now use the usb_debug()
printing funtion that already exists in usb.h.

Change-Id: I2199814de3327417417eb2e26a660f4a5557cb9f
Signed-off-by: Dave Frodin <dave.frodin@se-eng.com>
Reviewed-on: http://review.coreboot.org/2044
Tested-by: build bot (Jenkins)
Reviewed-by: Anton Kochkov <anton.kochkov@gmail.com>
diff --git a/payloads/libpayload/drivers/usb/usbhid.c b/payloads/libpayload/drivers/usb/usbhid.c
index 6af2568..ee8ba63 100644
--- a/payloads/libpayload/drivers/usb/usbhid.c
+++ b/payloads/libpayload/drivers/usb/usbhid.c
@@ -407,11 +407,11 @@
 
 		/* Found, changing keyboard layout */
 		map = &keyboard_layouts[i];
-		printf("  Keyboard layout '%s'\n", map->country);
+		usb_debug("  Keyboard layout '%s'\n", map->country);
 		return 0;
 	}
 
-	printf("  Keyboard layout '%s' not found, using '%s'\n",
+	usb_debug("  Keyboard layout '%s' not found, using '%s'\n",
 			country, map->country);
 
 	/* Nothing found, not changed */