1) OF unittest platform device

** unittest

Required properties:
- compatible: must be "unittest"

All other properties are optional.

Example:
	unittest {
		compatible = "unittest";
	};

2) OF unittest i2c adapter platform device

** platform device unittest adapter

Required properties:
- compatible: must be unittest-i2c-bus

Children nodes contain unittest i2c devices.

Example:
	unittest-i2c-bus {
		compatible = "unittest-i2c-bus";
	};

3) OF unittest i2c device

** I2C unittest device

Required properties:
- compatible: must be unittest-i2c-dev

All other properties are optional

Example:
	unittest-i2c-dev {
		compatible = "unittest-i2c-dev";
	};

4) OF unittest i2c mux device

** I2C unittest mux

Required properties:
- compatible: must be unittest-i2c-mux

Children nodes contain unittest i2c bus nodes per channel.

Example:
	unittest-i2c-mux {
		compatible = "unittest-i2c-mux";
		#address-cells = <1>;
		#size-cells = <0>;
		channel-0 {
			reg = <0>;
			#address-cells = <1>;
			#size-cells = <0>;
			i2c-dev {
				reg = <8>;
				compatible = "unittest-i2c-dev";
			};
		};
	};