Required properties:
- compatible : compatible list, one of "snps,spear-ahci",
"snps,exynos5440-ahci", "ibm,476gtr-ahci",
- "allwinner,sun4i-a10-ahci", "fsl,imx53-ahci" or
- "fsl,imx6q-ahci"
+ "allwinner,sun4i-a10-ahci", "fsl,imx53-ahci"
+ "fsl,imx6q-ahci" or "snps,dwc-ahci"
- interrupts : <interrupt mapping for SATA IRQ>
- reg : <registers mapping>