drivers: udc_dwc2: Disable control IN endpoint on SETUP

New control transfer is started prematurely from device perspective when
host timeout occurs. Any data transfer from previous control transfer
have to be cancelled prior to handling SETUP data. Unconditionally
disable control IN endpoint to prevent race for enqueued buffer between
udc_buf_get_all() called in dwc2_handle_evt_setup() and udc_buf_peek()
called in dwc2_handle_in_xfercompl().

Signed-off-by: Tomasz Moń <tomasz.mon@nordicsemi.no>