[lpc43xx][udc] improve endpoint clear feature
[lpc43xx][udc] improve endpoint clear feature

skabet/lk,hollanderic/lkstuff,srodrig1/lk,srodrig1/lk,hollanderic/lkstuff,nvll/lk,nvll/lk,srodrig1/lk,ErikCorryGoogle/lk,ErikCorryGoogle/lk,minglun-tsai/lk,minglun-tsai/lk,nvll/lk,ErikCorryGoogle/lk,srodrig1/lk,travisg/lk,littlekernel/lk,littlekernel/lk,hollanderic/lkstuff,sndnvaps/lk,nvll/lk,skabet/lk,srodrig1/lk,skabet/lk,travisg/lk,minglun-tsai/lk,ErikCorryGoogle/lk,minglun-tsai/lk,sndnvaps/lk,littlekernel/lk,littlekernel/lk,skabet/lk,skabet/lk,travisg/lk,travisg/lk,nvll/lk,hollanderic/lkstuff,sndnvaps/lk,sndnvaps/lk,sndnvaps/lk