Silicon Image SiI9234 HDMI/MHL bridge bindings

Required properties:
	- compatible : "sil,sii9234".
	- reg : I2C address for TPI interface, use 0x39
	- avcc33-supply : MHL/USB Switch Supply Voltage (3.3V)
	- iovcc18-supply : I/O Supply Voltage (1.8V)
	- avcc12-supply : TMDS Analog Supply Voltage (1.2V)
	- cvcc12-supply : Digital Core Supply Voltage (1.2V)
	- interrupts: interrupt specifier of INT pin
	- reset-gpios: gpio specifier of RESET pin (active low)
	- video interfaces: Device node can contain two video interface port
			    nodes for HDMI encoder and connector according to [1].
			    - port@0 - MHL to HDMI
			    - port@1 - MHL to connector

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


Example:
	sii9234@39 {
		compatible = "sil,sii9234";
		reg = <0x39>;
		avcc33-supply = <&vcc33mhl>;
		iovcc18-supply = <&vcc18mhl>;
		avcc12-supply = <&vsil12>;
		cvcc12-supply = <&vsil12>;
		reset-gpios = <&gpf3 4 GPIO_ACTIVE_LOW>;
		interrupt-parent = <&gpf3>;
		interrupts = <5 IRQ_TYPE_LEVEL_HIGH>;

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

			port@0 {
				reg = <0>;
				mhl_to_hdmi: endpoint {
					remote-endpoint = <&hdmi_to_mhl>;
				};
			};
			port@1 {
				reg = <1>;
				mhl_to_connector: endpoint {
					remote-endpoint = <&connector_to_mhl>;
				};
			};
		};
	};