renaming switches, new channel alignment

in order to have a clear structure switches have been renamed so that
they match now the labels on the t5x hacking board.
- SW1 two-pos switch
- SW2 tri-pos switch
- SW3 tri-pos switch

also channel alingment has is now as follows:
AIL
ELE
THR
RUD
SW1 (AUX1)
SW2 (AUX2)
SW3 (AUX3)
PotiA6

this should help to keep the code more clean and easy to
read/understand/navigate/extend...