Add support for PCI NE2000 clones. I finally got around to doing this :-)

Add support for PCI NE2000 clones.  I finally got around to doing this :-)
Tested on alpha, should work on i386 as well.  Note that we treat
a PCI NE2000 as a 16-bit card for now since the driver can not
deal with > 16 bit cards.  To fix this isa16bit in ed_softc needs to
be changed to bus_width (in bytes).  I plan to do this as part
of the split ed driver.