- Use more consistent and portable types in the softc.
- Map registers using an array of bus_size_t offsets, and set up the
mapping in the attach code (thanks to Jason Thorpe for suggesting
this!).
- Disable the ae-specific watchdog, which is no longer necessary in
the general case.
Still remaining: split out functions used to copy data to/from the
card, and retain a way to have a local driver name with the MI code.