langwell_udc: STALL the bad setFeature/clearFeature request

langwell_udc: STALL the bad setFeature/clearFeature request

BZ: 26747

As the USB spec request, a SetFeature() or ClearFeature() that
references a feature that cannot be set or that does not exist
should causes STALL to be returned in the Status stage of the
request.

Change-Id: I118d32bd7e5f4e66f4c23d109c9186c8898657a7
Signed-off-by: Li Wenji <wenji.li@intel.com>
Reviewed-on: http://android.intel.com:8080/37939
Reviewed-by: Zhuang, Jin Can <jin.can.zhuang@intel.com>
Reviewed-by: Tang, Richard <richard.tang@intel.com>
Reviewed-by: Saripalli, Ramakrishna <ramakrishna.saripalli@intel.com>
Reviewed-by: Meng, Zhe <zhe.meng@intel.com>
Tested-by: Meng, Zhe <zhe.meng@intel.com>
Reviewed-by: Wu, Hao <hao.wu@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>