(Placeholder note while we locate the kernel Tegra20 bindings)

Added in U-Boot:

Required properties:
 - clocks : Two clocks must be given, each as a phandle to the Tegra's
	    CAR node and the clock number as a parameter:
     - the I2C clock to use for the peripheral
     - the pll_p_out3 clock, which can be used for fast operation. This
	  does not change and is the same for all I2C nodes.

Example:
(TODO: merge with existing example):

	i2c@7000c400 {
		#address-cells = <1>;
		#size-cells = <0>;
		compatible = "nvidia,tegra20-i2c";
		reg = <0x7000C400 0x100>;
		interrupts = < 116 >;
		/* PERIPH_ID_I2C2, PLL_P_OUT3 */
		clocks = <&tegra_car 54>, <&tegra_car 124>;
	};
