Device-Tree bindings for Ingenic JZ4780 HDMI Transmitter

The HDMI Transmitter in the Ingenic JZ4780 is a Synopsys DesignWare HDMI 1.4
TX controller IP with accompanying PHY IP.

Required properties:
 - #address-cells : should be <1>
 - #size-cells : should be <0>
 - compatible : should be "ingenic,jz4780-hdmi"
 - reg-io-width: must be <4>
 - clocks: phandle to isrf and iahb clocks
 - clock-names : must be "isrf" and "iahb"
 - ports: Port nodes with endpoint definitions as defined in
   Documentation/devicetree/bindings/media/video-interfaces.txt,

Optional properties:
 - ddc-i2c-bus: phandle of an I2C controller used for DDC EDID probing

example:

hdmi: hdmi@10180000 {
	compatible = "ingenic,jz4780-hdmi";
	reg = <0x10180000 0x8000>;
	reg-io-width = <4>;
	ddc-i2c-bus = <&i2c4>;
	interrupt-parent = <&intc>;
	interrupts = <3>;
	clocks = <&cgu JZ4780_CLK_HDMI>, <&cgu JZ4780_CLK_AHB0>;
	clock-names = "isfr", "iahb";

	ports {
		hdmi_in: port {
			#address-cells = <1>;
			#size-cells = <0>;
			hdmi_in_lcd: endpoint@0 {
				reg = <0>;
				remote-endpoint = <&jz4780_out_hdmi>;
			};
		};
	};
};
