as the only argument and cast this as appropriate now that the function
pointers to the interrupt registration functions are fully prototyped.
Use <machine/conf.h> for the declarations of the device driver entry
points.
- 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.
