dt-bindings: Add INNOLUX P079ZCA panel bindings

The Innolux P079ZCA is a 7.85" panel with a 768X1024 resolution and
connected to DSI using four lanes.
Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1490316692-20506-1-git-send-email-zyw@rock-chips.com

Documentation/devicetree/bindings/display/panel/innolux,p079zca.txt

+Innolux P079ZCA 7.85" 768x1024 TFT LCD panel
+
+Required properties:
+- compatible: should be "innolux,p079zca"
+- reg: DSI virtual channel of the peripheral
+- power-supply: phandle of the regulator that provides the supply voltage
+- enable-gpios: panel enable gpio
+
+Optional properties:
+- backlight: phandle of the backlight device attached to the panel
+
+Example:
+
+	&mipi_dsi {
+		panel {
+			compatible = "innolux,p079zca";
+			reg = <0>;
+			power-supply = <...>;
+			backlight = <&backlight>;
+			enable-gpios = <&gpio1 13 GPIO_ACTIVE_HIGH>;
+			status = "okay";
+		};
+	};