properly from the beginning:
1) The `kern_devconf' struct should be a part of the driver's
`softc' structure (now it is).
2) The `description' should say what the device actually is,
rather than just giving a model number (now it does).
3) The device should be registered even if the probe fails, so
that it can be reconfigured later.
4) For netifs, the device state should follow the IFF_UP flag.
Other network interfaces should follow this example. (Please?) Eventually
there should be a rundown routine doing the equivalent of setting IFF_UP
off, and perhaps more if warranted.
9fe40fb5dd