dt-bindings: display: convert kingdisplay,kd097d04 to DT Schema

kingdisplay,kd097d04 matches the panel-simple-dsi binding.
The only difference is that enable-gpios is now an optional
property.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Nickey Yang <nickey.yang@rock-chips.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200408195109.32692-15-sam@ravnborg.org

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@0 {
-			compatible = "kingdisplay,kd097d04";
-			reg = <0>;
-			power-supply = <...>;
-			backlight = <&backlight>;
-			enable-gpios = <&gpio1 13 GPIO_ACTIVE_HIGH>;
-		};
-	};

Documentation/devicetree/bindings/display/panel/panel-simple-dsi.yaml

@@ -29,6 +29,8 @@ properties:
       # compatible must be listed in alphabetical order, ordered by compatible.
       # The description in the comment is mandatory for each compatible.
 
+        # Kingdisplay KD097D04 9.7" 1536x2048 TFT LCD panel
+      - kingdisplay,kd097d04
         # Panasonic 10" WUXGA TFT LCD panel
       - panasonic,vvx10f034n00