tap_move_ndx() function

Function tap_move_ndx when given a stable state, returns an index from 0-5. The index corresponds to a sequence of stable states which are given in this order: { TAP_RESET, TAP_IDLE, TAP_DRSHIFT, TAP_DRPAUSE, TAP_IRSHIFT, TAP_IRPAUSE } This sequence corresponds to look up tables which are used in some of the cable drivers.