usb: dwc2: gadget: Add dwc2_gadget_incr_frame_num()

Increases and checks targeted frame number of current ep
if overrun happened, sets flag and masks with DSTS_SOFFN_LIMIT

Added following fields to struct dwc2_hsotg_ep
-target_frame: Targeted frame num to setup next ISOC transfer
-frame_overrun: Indicates SOF number overrun in DSTS

Tested-by: John Keeping <john@metanate.com>
Signed-off-by: Vardan Mikayelyan <mvardan@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>