PixArt pat9125 rotating switch

The Pixart's PAT9125 controller is connected to the host processor via I2C.
It detects the rotation when user rotates the switch and generates interrupt
to the Host processor. The host processor reads the direction and number of
steps over I2C and passes the data to the rest of the system.

Required properties:
 - compatible	: should be "pixart,pat9125".
 - reg	: i2c slave address of the device.
 - interrupt-parent	: parent of interrupt.
 - interrupts	: interrupt to indicate motion of the rotating switch.
 - vdd-supply	: Power supply needed to power up the device.
 - vld-supply	: Power source required to power up I2C bus.

Optional properties:
 - pixart,inverse-x 	: boolean, use this to invert the x data before sending it to input
			framework.
 - pixart,inverse-y 	: boolean, use this to invert the y data before sending it to input
			framework.
 - pixart,press-enabled : boolean, use this to enable detection of pressing the button.
 - pinctrl-names	: This should be defined if a target uses pinctrl framework.
			See "pinctrl" in Documentation/devicetree/bindings/pinctrl/msm-pinctrl.txt
			It should specify the names of the configs that pinctrl can
			install in driver.
			Following are the pinctrl configs that can be installed:
			"pmx_rot_switch_active" : Active configuration of pins,
						it should specify active config
						defined in pin groups of
						interrupt gpio.
			"pmx_rot_switch_suspend" : Disabled configuration of
						 pins, it should specify sleep
						 config defined in pin groups
						 of interrupt gpio.
			"pmx_rot_switch_release" : Release configuration of
						 pins, it should specify release
						 config defined in pin groups of
						 interrupt gpio.
 - pixart,irq-gpio	: This should be defined if a target doesn't use pinctrl framework.
			irq gpio, which is to provide interrupts to host, same as "interrupts" node.

Required properties if 'pixart,press-enabled' DT property is defined:
 - pixart,press-keycode	: keycode to be sent when press is detected by the driver.

Example:
	pixart_pat9125@75 {
		compatible = "pixart,pat9125";
		reg = <0x75>;
		interrupt-parent = <&msm_gpio>;
		interrupts = <98 0x2008>;
		vdd-supply = <&pm8110_l5>;
		vld-supply = <&pm8110_l17>;
		pixart,irq-gpio = <&msm_gpio 98 0x2008>;
		pinctrl-names = "pmx_rot_switch_active",
				"pmx_rot_switch_suspend",
				"pmx_rot_switch_release";
		pinctrl-0 = <&pix_int_active>;
		pinctrl-1 = <&pix_int_suspend>;
		pinctrl-2 = <&pix_release>;
	};