dt-bindings: tc358754: add DT bindings

TC358764 MIPI-DSI to LVDS panel bridge

Required properties:

  - compatible: "toshiba,tc358764"

  - reg: the virtual channel number of a DSI peripheral

  - vddc-supply: core voltage supply, 1.2V

  - vddio-supply: I/O voltage supply, 1.8V or 3.3V

  - vddlvds-supply: LVDS1/2 voltage supply, 3.3V

  - reset-gpios: a GPIO spec for the reset pin

The device node can contain following 'port' child nodes,

according to the OF graph bindings defined in [1]:

  0: DSI Input, not required, if the bridge is DSI controlled

  1: LVDS Output, mandatory

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

Example:

	bridge@0 {

		reg = <0>;

		compatible = "toshiba,tc358764";

		vddc-supply = <&vcc_1v2_reg>;

		vddio-supply = <&vcc_1v8_reg>;

		vddlvds-supply = <&vcc_3v3_reg>;

		reset-gpios = <&gpd1 6 GPIO_ACTIVE_LOW>;

		#address-cells = <1>;

		#size-cells = <0>;

		port@1 {

			reg = <1>;

			lvds_ep: endpoint {

				remote-endpoint = <&panel_ep>;

			};

		};

	};