dt-bindings: Add TPO TPG110 binding

This adds device tree bindings for the TPO TPG110 panel found
mounted in the Nomadik NHK8815.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/display/panel/tpo,tpg110.txt

+TPO TPG110 Panel
+================
+
+This binding builds on the DPI bindings, adding a few properties
+as a superset of a DPI. See panel-dpi.txt for the required DPI
+bindings.
+
+Required properties:
+- compatible : "tpo,tpg110"
+- grestb-gpios : panel reset GPIO
+- scen-gpios : serial control enable GPIO
+- scl-gpios : serial control clock line GPIO
+- sda-gpios : serial control data line GPIO
+
+Required nodes:
+- Video port for DPI input, see panel-dpi.txt
+- Panel timing for DPI setup, see panel-dpi.txt
+
+Example
+-------
+
+panel {
+	compatible = "tpo,tpg110", "panel-dpi";
+	grestb-gpios = <&stmpe_gpio44 5 GPIO_ACTIVE_LOW>;
+	scen-gpios = <&gpio0 6 GPIO_ACTIVE_LOW>;
+	scl-gpios = <&gpio0 5 GPIO_ACTIVE_HIGH>;
+	sda-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>;
+	backlight = <&bl>;
+
+	port {
+		nomadik_clcd_panel: endpoint {
+			remote-endpoint = <&nomadik_clcd_pads>;
+		};
+	};
+
+	panel-timing {
+		clock-frequency = <33200000>;
+		hactive = <800>;
+		hback-porch = <216>;
+		hfront-porch = <40>;
+		hsync-len = <1>;
+		vactive = <480>;
+		vback-porch = <35>;
+		vfront-porch = <10>;
+		vsync-len = <1>;
+	};
+};