bus-independent core driver. Tested on all three bus types, including
an isa 3c509 masquerading as an eisa device (use ep* at eisa? slot ? in
your kernel config file to catch this one).
XXX Driver still needs to be converted to <machine/bus.h>
multiport cards no longer need 'flags 1', because the "don't set IEN"
requirement is communicated by the commulti_attach_args. com.c no longer
recognizes 'flags 1' at all.
now has a single device tree (rather than a forest). Also, attach
EISA only if it's present, and attach in order: PCI, EISA, ISA (most
specific to least specific).