- split softc size and match/attach out from cfdriver into
a new struct cfattach.
- new "attach" directive for files.*. May specify the name of
the cfattach structure, so that devices may be easily attached
to parents with different autoconfiguration semantics.
Support for multiple register banks on SBUS devices (based on patches
from Francis Dupont).
Highlights:
romaux defines an array of register spaces.
pay attention to `vactype'.
quirks handling 4/100 idiosyncracies.