watchdog: imx2_wdt: add device tree probe support

Adds device tree probe support for imx2_wdt driver.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index 86f7cac..b8ef2c6 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -329,12 +329,18 @@
 	}
 }
 
+static const struct of_device_id imx2_wdt_dt_ids[] = {
+	{ .compatible = "fsl,imx21-wdt", },
+	{ /* sentinel */ }
+};
+
 static struct platform_driver imx2_wdt_driver = {
 	.remove		= __exit_p(imx2_wdt_remove),
 	.shutdown	= imx2_wdt_shutdown,
 	.driver		= {
 		.name	= DRIVER_NAME,
 		.owner	= THIS_MODULE,
+		.of_match_table = imx2_wdt_dt_ids,
 	},
 };