Conexant Digicolor I2C controller

Required properties:
 - compatible: must be "cnxt,cx92755-i2c"
 - reg: physical address and length of the device registers
 - interrupts: a single interrupt specifier
 - clocks: clock for the device
 - #address-cells: should be <1>
 - #size-cells: should be <0>

Optional properties:
- clock-frequency: the desired I2C bus clock frequency in Hz; in
  absence of this property the default value is used (100 kHz).

Example:

	i2c: i2c@f0000120 {
		compatible = "cnxt,cx92755-i2c";
		reg = <0xf0000120 0x10>;
		interrupts = <28>;
		clocks = <&main_clk>;
		clock-frequency = <100000>;
		#address-cells = <1>;
		#size-cells = <0>;
	};
