Updated declarations of attach and probe functions.
Don't define dummy functions for un-supported bus space operations,
instead use the bs_notimp*() functions.
Some of the stuff (e.g., rarpd, bootpd, dhcpd etc., libsa) still will
only support Ethernet. Tcpdump itself should be ok, but libpcap needs
lot of work.
For the detailed change history, look at the commit log entries for
the is-newarp branch.
