arm: dts: s700: add node for ethernet controller

This patch adds node for ethernet controller found on Action Semi OWL
S700 SoC.

Since, there is no upstream Linux binding exist for S700 ethernet
controller, Changes are put in u-boot specific dtsi file.
Signed-off-by: NAmit Singh Tomar <amittomer25@gmail.com>

arch/arm/dts/s700-u-boot.dtsi

@@ -6,6 +6,19 @@
 /{
 	soc {
 		u-boot,dm-pre-reloc;
+
+		gmac:  ethernet@e0220000 {
+			compatible = "actions,s700-ethernet";
+			reg = <0 0xe0220000 0 0x2000>;
+			interrupts = <GIC_SPI 55 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "macirq";
+			local-mac-address = [ 00 18 fe 66 66 66 ];
+			clocks = <&cmu CLK_ETHERNET>, <&cmu CLK_RMII_REF>;
+			clock-names = "ethernet", "rmii_ref";
+			phy-mode = "rmii";
+			status = "okay";
+                };
+
 	};
 };