Input: melfas_mip4 - add devicetree binding documentations

Add devicetree binding documentations.
Signed-off-by: Sangwon Jee <jeesw@melfas.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation/devicetree/bindings/input/touchscreen/melfas_mip4.txt

+* MELFAS MIP4 Touchscreen
+
+Required properties:
+- compatible: must be "melfas,mip4_ts"
+- reg: I2C slave address of the chip (0x48 or 0x34)
+- interrupt-parent: interrupt controller to which the chip is connected
+- interrupts: interrupt to which the chip is connected
+
+Optional properties:
+- ce-gpios: GPIO connected to the CE (chip enable) pin of the chip
+
+Example:
+	i2c@00000000 {
+		touchscreen: melfas_mip4@48 {
+			compatible = "melfas,mip4_ts";
+			reg = <0x48>;
+			interrupt-parent = <&gpio>;
+			interrupts = <0 IRQ_TYPE_EDGE_FALLING>;
+			ce-gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
+		};
+	};

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -143,6 +143,7 @@ marvell	Marvell Technology Group Ltd.
 maxim	Maxim Integrated Products
 mediatek	MediaTek Inc.
 melexis	Melexis N.V.
+melfas	MELFAS Inc.
 merrii	Merrii Technology Co., Ltd.
 micrel	Micrel Inc.
 microchip	Microchip Technology Inc.