devicetree/bindings: display: bridge: Add LVDS encoder DT bindings

The DT bindings support parallel to LVDS encoders that don't require any
configuration, similarly to the dumb VGA DAC DT bindings.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170302104728.7150-2-laurent.pinchart+renesas@ideasonboard.com

Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt

+Parallel to LVDS Encoder
+------------------------
+
+This binding supports the parallel to LVDS encoders that don't require any
+configuration.
+
+LVDS is a physical layer specification defined in ANSI/TIA/EIA-644-A. Multiple
+incompatible data link layers have been used over time to transmit image data
+to LVDS panels. This binding targets devices compatible with the following
+specifications only.
+
+[JEIDA] "Digital Interface Standards for Monitor", JEIDA-59-1999, February
+1999 (Version 1.0), Japan Electronic Industry Development Association (JEIDA)
+[LDI] "Open LVDS Display Interface", May 1999 (Version 0.95), National
+Semiconductor
+[VESA] "VESA Notebook Panel Standard", October 2007 (Version 1.0), Video
+Electronics Standards Association (VESA)
+
+Those devices have been marketed under the FPD-Link and FlatLink brand names
+among others.
+
+
+Required properties:
+
+- compatible: Must be "lvds-encoder"
+
+Required nodes:
+
+This device has two video ports. Their connections are modeled using the OF
+graph bindings specified in Documentation/devicetree/bindings/graph.txt.
+
+- Video port 0 for parallel input
+- Video port 1 for LVDS output
+
+
+Example
+-------
+
+lvds-encoder {
+	compatible = "lvds-encoder";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	ports {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		port@0 {
+			reg = <0>;
+
+			lvds_enc_in: endpoint {
+				remote-endpoint = <&display_out_rgb>;
+			};
+		};
+
+		port@1 {
+			reg = <1>;
+
+			lvds_enc_out: endpoint {
+				remote-endpoint = <&lvds_panel_in>;
+			};
+		};
+	};
+};