Drochner's work made in nisimura-pmax-wscons branch. Still a little
to do before useful for DECstation. MI softintr required.
- allow wildcard matchs to have zstty/zskbd/zsms in default hardware
configuration.
- abandon to check zs_ioasic_cnattach() return value; it doesn't fail.
- have zs_ioasic_cnattach() serial line parameters hardcoded inside, in
symmetry with zs_ioasic_lk201_cnattach().
nisimura