chained podule interrupt handlers.
Fill out the ih_maskaddr and ih_maskbits fields in the interrupt handler
structure so that interrupt dispatcher knows where to look to determine
if the handler should be called.
General code tidy up and source code formatting.
device and a printable "external name" (name + unit number), thus eliminating
if_name and if_unit. Updated interface to (*if_watchdog)() and (*if_start)()
to take a struct ifnet *, rather than a unit number.
matchpodule() is now used to test podule_attach_args for correct id's.
Moved the probing code that used the softc into the attach function.
Fixed compiler warnings generated with -Wall.
- 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.