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.
for the same purpose (ignoring invalid interrupts).
For cards that are not able to stop all interrupts (or we don't know a way
to do that in software, at least) run the clearirq callback even when
ignoring an interrupt because we are not enabled. Otherwise the card would
stop interrupting.
Reserve a driver specific callout handle and an int value in the generic
isic_softc to allow card drivers to implement fancy blinkenlights.
(de)activate for pcmcia cards.
Implement detach/(de)activate for PCI cards.
Clean up internal state (free call-descriptors) if a controller is
detached while it has open connections.
B-channel and D-channel drivers separately) split the Fritz!PCI card
driver out of the isic driver.
The new device is called "ifpci" and uses the same D-channel driver as the
isic devices, but has it's own B-channel driver.