drm: bridge: add DT bindings for TI ths8135

THS8135 Video DAC

-----------------

This is the binding for Texas Instruments THS8135 Video DAC bridge.

Required properties:

- compatible: Must be "ti,ths8135"

Required nodes:

This device has two video ports. Their connections are modelled using the OF

graph bindings specified in Documentation/devicetree/bindings/graph.txt.

- Video port 0 for RGB input

- Video port 1 for VGA output

Example

-------

vga-bridge {

	compatible = "ti,ths8135";

	#address-cells = <1>;

	#size-cells = <0>;

	ports {

		#address-cells = <1>;

		#size-cells = <0>;

		port@0 {

			reg = <0>;

			vga_bridge_in: endpoint {

				remote-endpoint = <&lcdc_out_vga>;

			};

		};

		port@1 {

			reg = <1>;

			vga_bridge_out: endpoint {

				remote-endpoint = <&vga_con_in>;

			};

		};

	};

};