Documentation: DT: Add ASM330 IMU DT Bindings

The ASM330 is a highly integrated, low power inertial measurement unit (IMU)

that provides precise acceleration and angular rate (gyroscopic) measurement.

To enable driver probing, add the asm330lhh node to the platform device tree as described below.

Required properties:

- compatible: "st,asm330lhh"

- reg: the I2C address or SPI chip select the device will respond to

- vio-supply: 1.8V regulator supply

- vdd-supply: 3V regulator supply

- interrupt-parent: phandle to the parent interrupt controller as documented in [interrupts][4]

- interrupts: interrupt mapping for IRQ as documented in [interrupts][4]

Recommended properties for SPI bus usage:

- spi-max-frequency: maximum SPI bus frequency as documented in [SPI][3]

Optional properties:

- st,drdy-int-pin: MEMS sensor interrupt line to use (default 1)

I2C example (based on Raspberry PI 3):

	&i2c0 {

		status = "ok";

		#address-cells = <0x1>;

		#size-cells = <0x0>;

		asm330lhh@6b {

			compatible = "st,asm330lhh";

			reg = <0x6b>;

			interrupt-parent = <&gpio>;

			interrupts = <26 IRQ_TYPE_EDGE_RISING>;

		};

SPI example (based on Raspberry PI 3):

	&spi0 {

		status = "ok";

		#address-cells = <0x1>;

		#size-cells = <0x0>;

		asm330lhh@0 {

			spi-max-frequency = <500000>;

			compatible = "st,asm330lhh";

			reg = <0>;

			interrupt-parent = <&gpio>;

			interrupts = <26 IRQ_TYPE_EDGE_RISING>;

		};