Revert "usb: dwc3: gadget: skip Set/Clear Halt when invalid"

This reverts commit ffb80fc6.

Turns out that commit is wrong. Host controllers are allowed to use
Clear Feature HALT as means to sync data toggle between host and
periperal.

Cc: <stable@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>