usb: dwc3: gadget: Execute gadget stop after halting the controller

Do not call gadget stop until the poll for controller halt is
completed.  DEVTEN is cleared as part of gadget stop, so the intention to
allow ep0 events to continue while waiting for controller halt is not
happening.

Fixes: c9668379

 ("usb: dwc3: ep0: Don't prepare beyond Setup stage")
Cc: stable@vger.kernel.org
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/20230420212759.29429-2-quic_wcheng@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>