The dwc3 UDC driver doesn't implement endpoint wedging correctly.
When an endpoint is wedged, the gadget driver should be allowed to
clear the wedge by calling usb_ep_clear_halt().  Only the host is
prevented from resetting the endpoint.

This patch fixes the implementation.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Pratyush Anand <pratyush.anand@st.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>