arm/dts: add wdt node for omap3 and omap4

Add wdt node to support dt.

Signed-off-by: Xiao Jiang <jgq516@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/boot/dts/omap4.dtsi b/arch/arm/boot/dts/omap4.dtsi
index 359c497..3664641 100644
--- a/arch/arm/boot/dts/omap4.dtsi
+++ b/arch/arm/boot/dts/omap4.dtsi
@@ -272,5 +272,10 @@
 			ti,hwmods = "mmc5";
 			ti,needs-special-reset;
 		};
+
+		wdt2: wdt@4a314000 {
+			compatible = "ti,omap4-wdt", "ti,omap3-wdt";
+			ti,hwmods = "wd_timer2";
+		};
 	};
 };