usb: dwc2: gadget: fix phy interface configuration

hsotg->phyif is set in dwc2_gadget_init according to phy interface
width. Use it for configuration instead of hardcoded value.
Moreover, set USB turnaround time according to phy width.

Tested-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>