usb: dwc2: Set actual frame number for completed ISOC transfer

On ISOC transfer completion, in DDMA mode, set actual frame
number returning to function driver in usb_request.

Due to core limitation, returning frame number is 11-bit wide.

Signed-off-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>