Silicon Image SiI8620 HDMI/MHL bridge bindings

Required properties:
	- compatible: "sil,sii8620"
	- reg: i2c address of the bridge
	- cvcc10-supply: Digital Core Supply Voltage (1.0V)
	- iovcc18-supply: I/O Supply Voltage (1.8V)
	- interrupts, interrupt-parent: interrupt specifier of INT pin
	- reset-gpios: gpio specifier of RESET pin
	- clocks, clock-names: specification and name of "xtal" clock
	- video interfaces: Device node can contain video interface port
			    node for HDMI encoder according to [1].

[1]: Documentation/devicetree/bindings/media/video-interfaces.txt

Example:
	sii8620@39 {
		reg = <0x39>;
		compatible = "sil,sii8620";
		cvcc10-supply = <&ldo36_reg>;
		iovcc18-supply = <&ldo34_reg>;
		interrupt-parent = <&gpf0>;
		interrupts = <2 0>;
		reset-gpio = <&gpv7 0 0>;
		clocks = <&pmu_system_controller 0>;
		clock-names = "xtal";

		port {
			mhl_to_hdmi: endpoint {
				remote-endpoint = <&hdmi_to_mhl>;
			};
		};
	};