function is called when carrier is lost in lieu of a console message.
This is used by the sparc port to switch media types on Sun4m machines
if the appropriate link flags are set by ifconfig (see following commit
message). Should not affect ports that do not use sc_nocarrier().
naming conflicts between bus attachments on ports that can have
multiple instances of the LANCE.
Changed struct ifnet to have a pointer to the softc of the underlying
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.
remove their 'integrate' (usually defined to be 'static') keywords.
when lance drivers are split up by attachment, more than one file will
reference the copy/zero functions (i.e. not just the file that pulls in
am7990.c... and eventually inclusion of am7990.c should go away entirely).
