* Freescale MX233/MX28 SSP/SPI

Required properties:
- compatible: Should be "fsl,<soc>-spi", where soc is "imx23" or "imx28"
- reg: Offset and length of the register set for the device
- interrupts: Should contain SSP ERROR interrupt
- dmas: DMA specifier, consisting of a phandle to DMA controller node
  and SSP DMA channel ID.
  Refer to dma.txt and fsl-mxs-dma.txt for details.
- dma-names: Must be "rx-tx".

Optional properties:
- clock-frequency : Input clock frequency to the SPI block in Hz.
		    Default is 160000000 Hz.

Example:

ssp0: ssp@80010000 {
	#address-cells = <1>;
	#size-cells = <0>;
	compatible = "fsl,imx28-spi";
	reg = <0x80010000 0x2000>;
	interrupts = <96>;
	dmas = <&dma_apbh 0>;
	dma-names = "rx-tx";
};