dt-bindings: panel: Add Boe Himax8279d is 1200x1920, 4-lane MIPI-DSI LCD panel

The Boe Himax8279d is a 8.0" panel with a 1200x1920 resolution and
connected to DSI using four lanes.

V8:
- Modify communication address

V7:
- Add the information of the reviewer

V6:
- Add the information of the reviewer

V5:
- Added changelog

V4:
- None

V3:
- None

V2:
- Add compatible device "boe,himax8279d10p" (Sam)
- Add the necessary property descriptions (Sam)
Signed-off-by: Jerry Han <jerry.han.hq@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Derek Basehore <dbasehore@chromium.org>
Cc: Jitao Shi <jitao.shi@mediatek.com>
Cc: Rock wang <rock_wang@himax.com.cn>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190425031842.17202-1-jerry.han.hq@gmail.com

Documentation/devicetree/bindings/display/panel/boe,himax8279d.txt

+Boe Himax8279d 1200x1920 TFT LCD panel
+
+Required properties:
+- compatible: should be "boe,himax8279d8p" and one of: "boe,himax8279d10p"
+- reg: DSI virtual channel of the peripheral
+- enable-gpios: panel enable gpio
+- pp33-gpios: a GPIO phandle for the 3.3v pin that provides the supply voltage
+- pp18-gpios: a GPIO phandle for the 1.8v pin that provides the supply voltage
+
+Optional properties:
+- backlight: phandle of the backlight device attached to the panel
+
+Example:
+
+	&mipi_dsi {
+		panel {
+			compatible = "boe,himax8279d8p", "boe,himax8279d10p";
+			reg = <0>;
+			backlight = <&backlight>;
+			enable-gpios = <&gpio 45 GPIO_ACTIVE_HIGH>;
+			pp33-gpios = <&gpio 35 GPIO_ACTIVE_HIGH>;
+			pp18-gpios = <&gpio 36 GPIO_ACTIVE_HIGH>;
+		};
+	};