ARM: dts: rockchip: add watchdog node

This adds the Designware compatible watchdog found on RK3xxx Cortex-A9 SoCs.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
diff --git a/arch/arm/boot/dts/rk3066a.dtsi b/arch/arm/boot/dts/rk3066a.dtsi
index 9c34da4..879a818 100644
--- a/arch/arm/boot/dts/rk3066a.dtsi
+++ b/arch/arm/boot/dts/rk3066a.dtsi
@@ -425,3 +425,7 @@
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart3_xfer>;
 };
+
+&wdt {
+	compatible = "rockchip,rk3066-wdt", "snps,dw-wdt";
+};