aucc driver enhancements by Bernardo Innocenti

[Ignatios Souvatzis <is%jocelyn.rhein.de@localhost>]

Hello,

I've committed a (partially reformatted) version of the aucc changes that
Bernardo Innocenti submitted in PR 6787.

As my A3000 still isn't fully functional as a NetBSD machine, I can't test
them myself. So please do so, and either send short notices here or send-pr
serious bug reports.

Regards,
        Ignatios