ARM: highbank: add xgmac ethernet devices to dts

Add device nodes for xgmac ethernet block in Calxeda Highbank.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>

arch/arm/boot/dts/highbank.dts

@@ -194,5 +194,17 @@ dma@fff3d000 {
 			reg = <0xfff3d000 0x1000>;
 			interrupts = <0 92 4>;
 		};
+
+		ethernet@fff50000 {
+			compatible = "calxeda,hb-xgmac";
+			reg = <0xfff50000 0x1000>;
+			interrupts = <0 77 4  0 78 4  0 79 4>;
+		};
+
+		ethernet@fff51000 {
+			compatible = "calxeda,hb-xgmac";
+			reg = <0xfff51000 0x1000>;
+			interrupts = <0 80 4  0 81 4  0 82 4>;
+		};
 	};
 };