* I2C

Required Properties :

 - reg : Offset and length of the register set for the device
 - compatible : "socionext,f_i2c"
 - interrupts : interrupt the I2C IP is connected to in the SoC
 - clock-frequency : I2C bus clock frequency in Hz (100000 or 400000)

Example :

	i2c: sn_i2c {
		compatible = "socionext,sn_i2c";
		reg = <0xfff73000 0x1000>;
		interrupts = <0 91 0x4>;
		clock-frequency = <100000>;
	};
