NVIDIA Tegra20 MC(Memory Controller)

Required properties:
- compatible : "nvidia,tegra20-mc"
- reg : Should contain 2 register ranges(address and length); see the
  example below. Note that the MC registers are interleaved with the
  GART registers, and hence must be represented as multiple ranges.
- interrupts : Should contain MC General interrupt.
- #reset-cells : Should be 1. This cell represents memory client module ID.
  The assignments may be found in header file <dt-bindings/memory/tegra20-mc.h>
  or in the TRM documentation.

Example:
	mc: memory-controller@7000f000 {
		compatible = "nvidia,tegra20-mc";
		reg = <0x7000f000 0x024
		       0x7000f03c 0x3c4>;
		interrupts = <0 77 0x04>;
		#reset-cells = <1>;
	};

	video-codec@6001a000 {
		compatible = "nvidia,tegra20-vde";
		...
		resets = <&mc TEGRA20_MC_RESET_VDE>;
	};
