In elink_reset(), since some machines may have more than one ISA bus,
implement a way of keeping track of which ISA bus has received an
elink_reset(); The static variable which was used previously didn't
scale.
round: moving the drivers into a machine-independent directory.
Some drivers (e.g. fd.c) not moved because they use other pc features (e.g.
CMOS settings), and none of the non-driver files moved, because they're
still pretty much PC specific. eventually (when other ports with ISA
busses really start using this code), more 'high-level' ISA support will
live here.
