dt-bindings: Add KINGDISPLAY KD097D04 panel bindings

The KINGDISPLAY KD097D04 is a 9.7" panel with a 1536x2048
resolution and connected to DSI using 8 lanes.
Signed-off-by: Nickey Yang <nickey.yang@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180702103229.3952-3-heiko@sntech.de

Documentation/devicetree/bindings/display/panel/kingdisplay,kd097d04.txt

+Kingdisplay KD097D04 9.7" 1536x2048 TFT LCD panel
+
+Required properties:
+- compatible: should be "kingdisplay,kd097d04"
+- 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 = "kingdisplay,kd097d04";
+			reg = <0>;
+			power-supply = <...>;
+			backlight = <&backlight>;
+			enable-gpios = <&gpio1 13 GPIO_ACTIVE_HIGH>;
+		};
+	};