NVIDIA Tegra 20 GART

Required properties:
- compatible: "nvidia,tegra20-gart"
- reg: Two pairs of cells specifying the physical address and size of
  the memory controller registers and the GART aperture respectively.

Example:

	gart: gart@7000f000 {
		compatible = "nvidia,tegra20-gart";
		reg = < 0x7000f000 0x00000100    /* controller registers */
		        0x58000000 0x02000000 >; /* GART aperture */
	};