imx31: add watchdog device on litekit board.

This patch adds support for SoC build-in watchdog device on litekit
board.

Signed-off-by: Vladimir Zapolskiy <vzapolskiy@gmail.com>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-mx3/mx31lite-db.c

@@ -206,5 +206,6 @@ void __init mx31lite_db_init(void)
 	mxc_register_device(&mxcsdhc_device0, &mmc_pdata);
 	mxc_register_device(&mxc_spi_device0, &spi0_pdata);
 	platform_device_register(&litekit_led_device);
+	mxc_register_device(&imx_wdt_device0, NULL);
 }