dt-bindings: panel: Add Samsung S6E63M0 panel documentation

This commit adds documentation for Samsung S6E63M0 AMOLED LCD panel
driver.
Signed-off-by: Jonathan Bakker <xc-racer2@live.ca>
Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190222175153.20567-1-pawel.mikolaj.chmiel@gmail.com

Documentation/devicetree/bindings/display/panel/samsung,s6e63m0.txt

+Samsung s6e63m0 AMOLED LCD panel
+
+Required properties:
+  - compatible: "samsung,s6e63m0"
+  - reset-gpios: GPIO spec for reset pin
+  - vdd3-supply: VDD regulator
+  - vci-supply: VCI regulator
+
+The panel must obey rules for SPI slave device specified in document [1].
+
+The device node can contain one 'port' child node with one child
+'endpoint' node, according to the bindings defined in [2]. This
+node should describe panel's video bus.
+
+[1]: Documentation/devicetree/bindings/spi/spi-bus.txt
+[2]: Documentation/devicetree/bindings/media/video-interfaces.txt
+
+Example:
+
+		s6e63m0: display@0 {
+			compatible = "samsung,s6e63m0";
+			reg = <0>;
+			reset-gpio = <&mp05 5 1>;
+			vdd3-supply = <&ldo12_reg>;
+			vci-supply = <&ldo11_reg>;
+			spi-max-frequency = <1200000>;
+
+			port {
+				lcd_ep: endpoint {
+					remote-endpoint = <&fimd_ep>;
+				};
+			};
+		};