usb: dwc3: store driver data earlier

We need to store it before phys are handled, so we can later
use it in ULPI interface support code.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>