EXYNOS5: Add device node for USB.

This patch adds the device node required for USB
Signed-off-by: NVivek Gautam <gautam.vivek@samsung.com>
Signed-off-by: NMinkyu Kang <mk7.kang@samsung.com>

arch/arm/dts/exynos5250.dtsi

@@ -138,4 +138,17 @@
 		reg = <0x131b0000 0x30>;
 		interrupts = <0 130 0>;
 	};
+
+	ehci@12110000 {
+		compatible = "samsung,exynos-ehci";
+		reg = <0x12110000 0x100>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		phy {
+			compatible = "samsung,exynos-usb-phy";
+			reg = <0x12130000 0x100>;
+		};
+	};
+
 };