removing assumptions that there are only two B channels and by
adding support for a varying number of channels.
Due to this, rename previously used isdn identified "bri" to "isdnif",
which better describes the current situation.
The driver backend is capable of supporting also ISA cards (no DMA)
and primary rate (PRI) cards in addition to the basic rate ones,
but I don't any to test on right now, so we don't support those
currently.
This code was originally written by Juha-Matti Liukkonen <jml@cubical.fi>
of Cubical Solutions Ltd. for FreeBSD, and was ported to NetBSD by
myself for the same company.
dyoung