NVIDIA Tegra AHB

Required properties:
- compatible : For Tegra20, must contain "nvidia,tegra20-ahb".  For
  Tegra30, must contain "nvidia,tegra30-ahb".  Otherwise, must contain
  '"nvidia,<chip>-ahb", "nvidia,tegra30-ahb"' where <chip> is tegra124,
  tegra132, or tegra210.
- reg : Should contain 1 register ranges(address and length)

Example:
	ahb: ahb@6000c004 {
		compatible = "nvidia,tegra20-ahb";
		reg = <0x6000c004 0x10c>; /* AHB Arbitration + Gizmo Controller */
	};
