Input: melfas_mip4 - add devicetree binding documentations

* 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>;

		};

	};

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.