Hisilicon hieth controller

Required properties:
- compatible: should be "hisilicon,hieth".
- reg: specifies base physical address(s) and size of the device registers.
  The region is the MAC register base and size.
- interrupts: should contain the MAC interrupt.
- #address-cells: must be <1>.
- #size-cells: must be <0>.
- phy-mode: see ethernet.txt [1].
- phy-handle: see ethernet.txt [1].
- mac-address: see ethernet.txt [1].
- clocks: clock phandle and specifier pair.
- resets: reset controller phandle and specifier pair.

- PHY subnode: inherits from phy binding [2]

[1] Documentation/devicetree/bindings/net/ethernet.txt
[2] Documentation/devicetree/bindings/net/phy.txt

Example:
	hieth: ethernet@10050000 {
		compatible = "hisilicon,hieth";
		reg = <0x10050000 0x4000>;
		interrupts = <12>;

		clocks = <&clock HI3516CV300_ETH_CLK>;
		clock-names = "clk";

		resets = <&clock 0xcc 0>,
				<&clock 0xcc 3>;
		reset-names = "mac_reset",
				"phy0_reset";

		phy-handle = <&hieth_phy0>;

		#address-cells = <1>;
		#size-cells = <0>;

		hieth_phy0: hieth_phy@1 {
			reg = <1>;
			mac-address = [00 00 00 00 00 00];
			phy-mode = "mii";
		};
	};
