* NVIDIA Tegra Secure Digital Host Controller

This controller on Tegra family SoCs provides an interface for MMC, SD,
and SDIO types of memory cards.

Required properties:
- compatible : Should be "nvidia,<chip>-sdhci"
- reg : Should contain SD/MMC registers location and length
- interrupts : Should contain SD/MMC interrupt
- bus-width : Number of data lines, can be <1>, <4>, or <8>

Optional properties:
- cd-gpios : Specify GPIOs for card detection
- wp-gpios : Specify GPIOs for write protection
- power-gpios : Specify GPIOs for power control

Example:

sdhci@c8000200 {
	compatible = "nvidia,tegra20-sdhci";
	reg = <0xc8000200 0x200>;
	interrupts = <47>;
	cd-gpios = <&gpio 69 0>; /* gpio PI5 */
	wp-gpios = <&gpio 57 0>; /* gpio PH1 */
	power-gpios = <&gpio 155 0>; /* gpio PT3 */
	bus-width = <8>;
};