usb: dwc3: core: enable the USB2 and USB3 phy in probe

Enabled the USB2 and USB3 PHY in probe by calling usb_phy_set_suspend
and disabled the PHYs on driver removal. When PM is implemented this
will be optimized to enable the PHYs only when needed.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>