* Broadcom BCM2835 SoC I2S/PCM module

Required properties:
- compatible: "brcm,bcm2835-i2s"
- reg: Should contain PCM registers location and length.
- clocks: the (PCM) clock to use
- dmas: List of DMA controller phandle and DMA request line ordered pairs.
- dma-names: Identifier string for each DMA request line in the dmas property.
  These strings correspond 1:1 with the ordered pairs in dmas.

  One of the DMA channels will be responsible for transmission (should be
  named "tx") and one for reception (should be named "rx").

Example:

bcm2835_i2s: i2s@7e203000 {
	compatible = "brcm,bcm2835-i2s";
	reg = <0x7e203000 0x24>;
	clocks = <&clocks BCM2835_CLOCK_PCM>;

	dmas = <&dma 2>,
	       <&dma 3>;
	dma-names = "tx", "rx";
};
