phy: usb: USB driver is crashing during S3 resume on 7216

This is a result of the USB 2.0 clocks not being disabled/enabled
during suspend/resume on XHCI only systems.

Signed-off-by: Al Cooper <alcooperx@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>