usb: dwc2: fix transfer stop programming for out endpoint

To stop an out endpoint, software should set sets the Global OUT NAK,
but not the Global Non-periodic IN NAK. This driver bug leads the out-ep
failed be in disabled state with below error.

dwc2_hsotg_ep_stop_xfr: timeout DOEPCTL.EPDisable

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Du, Changbin <changbin.du@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>