* "fsl,imx23-usbphy" for imx23 and imx28
* "fsl,imx6q-usbphy" for imx6dq and imx6dl
* "fsl,imx6sl-usbphy" for imx6sl
+ * "fsl,imx6sx-usbphy" for imx6sx
"fsl,imx23-usbphy" is still a fallback for other strings
- reg: Should contain registers location and length
- interrupts: Should contain phy interrupt