* Freescale MXS MMC controller

The Freescale MXS Synchronous Serial Ports (SSP) can act as a MMC controller
to support MMC, SD, and SDIO types of memory cards.

Required properties:
- compatible: Should be "fsl,<chip>-mmc".  The supported chips include
  imx23 and imx28.
- reg: Should contain registers location and length
- interrupts: Should contain ERROR and DMA interrupts
- fsl,ssp-dma-channel: APBH DMA channel for the SSP
- bus-width: Number of data lines, can be <1>, <4>, or <8>

Optional properties:
- wp-gpios: Specify GPIOs for write protection

Examples:

ssp0: ssp@80010000 {
	compatible = "fsl,imx28-mmc";
	reg = <0x80010000 2000>;
	interrupts = <96 82>;
	fsl,ssp-dma-channel = <0>;
	bus-width = <8>;
};