[platform][stm32f7xx] fix addition of panic shell switch
[platform][stm32f7xx] fix addition of panic shell switch

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