Invensense MPU-3050 Gyroscope device tree bindings

Required properties:
  - compatible : should be "invensense,mpu3050"
  - reg : the I2C address of the sensor

Optional properties:
  - interrupt-parent : should be the phandle for the interrupt controller
  - interrupts : interrupt mapping for the trigger interrupt from the
    internal oscillator. The following IRQ modes are supported:
    IRQ_TYPE_EDGE_RISING, IRQ_TYPE_EDGE_FALLING, IRQ_TYPE_LEVEL_HIGH and
    IRQ_TYPE_LEVEL_LOW. The driver should detect and configure the hardware
    for the desired interrupt type.
  - vdd-supply : supply regulator for the main power voltage.
  - vlogic-supply : supply regulator for the signal voltage.
  - mount-matrix : see iio/mount-matrix.txt

Optional subnodes:
  - The MPU-3050 will pass through and forward the I2C signals from the
    incoming I2C bus, alternatively drive traffic to a slave device (usually
    an accelerometer) on its own initiative. Therefore is supports a subnode
    i2c gate node. For details see: i2c/i2c-gate.txt

Example:

mpu3050@68 {
	compatible = "invensense,mpu3050";
	reg = <0x68>;
	interrupt-parent = <&foo>;
	interrupts = <12 IRQ_TYPE_EDGE_FALLING>;
	vdd-supply = <&bar>;
	vlogic-supply = <&baz>;

	/* External I2C interface */
	i2c-gate {
		#address-cells = <1>;
		#size-cells = <0>;

		fnord@18 {
			compatible = "fnord";
			reg = <0x18>;
			interrupt-parent = <&foo>;
			interrupts = <13 IRQ_TYPE_EDGE_FALLING>;
		};
	};
};
