The SMI130 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 smi130_gyro and smi130_acc node to the platform
device tree as described below.

Required properties:

- compatible: "smi130_gyro", "smi130_acc"
- reg: the I2C address or SPI chip select the device will respond to
- 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:
- smi130_gyro,gpio_irq: MEMS sensor interrupt line to use (default 1)

I2C example (based on Raspberry PI 3):

        &i2c0 {
                status = "ok";
                #address-cells = <0x1>;
                #size-cells = <0x0>;
                smi130_gyro@68 {
                        compatible = "smi130_gyro";
                        reg = <0x68>;
                        interrupt-parent = <&gpio>;
                        interrupts = <26 IRQ_TYPE_EDGE_RISING>;
                };
                smi130_acc@18 {
                        compatible = "smi130_acc";
                        reg = <0x18>;
                        interrupt-parent = <&gpio>;
                        interrupts = <25 IRQ_TYPE_EDGE_RISING>;
                };

SPI example (based on Raspberry PI 3):

        &spi0 {
                status = "ok";
                #address-cells = <0x1>;
                #size-cells = <0x0>;
                smi130_gyro@68 {
                        compatible = "smi130_gyro";
                        reg = <0x68>;
                        interrupt-parent = <&gpio>;
                        interrupts = <26 IRQ_TYPE_EDGE_RISING>;
                };
                smi130_acc@18 {
                        compatible = "smi130_acc";
                        reg = <0x18>;
                        interrupt-parent = <&gpio>;
                        interrupts = <25 IRQ_TYPE_EDGE_RISING>;
                };
