mCube mc3xxx 3-axis accelerometer sensor driver.

Required properties:

 - compatible		: Should be "mcube,mc3xxx".
 - reg			: i2c slave address of the device.
 - pinctrl-names	: Pinctrl configuration names of this sensor driver.
				Should be "default".
 - pinctrl-0		: The pinctrl node corresponding to "default",
				Should be <&mc3xxx_default>.
 - interrupt-parent	: Parent of interrupt.
 - interrupts		: Accelerometer interrupt to indicate new data ready or events.
 - vdd-supply		: Analog power supply needed to power device.
 - vio-supply		: Digital IO power supply needed for IO and I2C.
 - mcube,position	: The orientation of the accelerometer on the board. There
				are 8 possible ways of positioning it:
				0: top, left-down
				1: top, right-down
				2: top, right-up
				3: top, left-up
				4: bottom, left-down
				5: bottom, right-down
				6: bottom, right-up
				7: bottom, left-up

Example:
&i2c_0 { /* BLSP1 QUP2 */
	 mcube@4c { /* Accelerometer sensor */
		compatible = "mcube,mc3xxx";
		reg = <0x4c>;
		pinctrl-names = "default";
		pinctrl-0 = <&mc3xxx_default>;
		interrupt-parent = <&msm_gpio>;
		interrupts = <115 0x2002>;
		vdd-supply = <&pm8916_l17>;
		vio-supply = <&pm8916_l6>;
		mcube,position = <1>;
	};
};