* mvebu (Kirkwood, Dove, Armada 370) audio controller

Required properties:

- compatible: "marvell,mvebu-audio"

- reg: physical base address of the controller and length of memory mapped
  region.

- interrupts: list of two irq numbers.
  The first irq is used for data flow and the second one is used for errors.

- clocks: one or two phandles.
  The first one is mandatory and defines the internal clock.
  The second one is optional and defines an external clock.

- clock-names: names associated to the clocks:
	"internal" for the internal clock
	"extclk" for the external clock

Example:

i2s1: audio-controller@b4000 {
	compatible = "marvell,mvebu-audio";
	reg = <0xb4000 0x2210>;
	interrupts = <21>, <22>;
	clocks = <&gate_clk 13>;
	clock-names = "internal";
};