* Energymicro efm32 i2c controller

Required properties :

 - reg : Offset and length of the register set for the device
 - compatible : should be "energymicro,efm32-i2c"
 - interrupts : the interrupt number
 - clocks : reference to the module clock

Recommended properties :

 - clock-frequency : maximal I2C bus clock frequency in Hz.
 - energymicro,location : Decides the location of the USART I/O pins.
   Allowed range : [0 .. 6]

Example:
	i2c0: i2c@4000a000 {
		#address-cells = <1>;
		#size-cells = <0>;
		compatible = "energymicro,efm32-i2c";
		reg = <0x4000a000 0x400>;
		interrupts = <9>;
		clocks = <&cmu clk_HFPERCLKI2C0>;
		clock-frequency = <100000>;
		energymicro,location = <3>;

		eeprom@50 {
			compatible = "microchip,24c02";
			reg = <0x50>;
			pagesize = <16>;
		};
	};