The bluetooth setup code actually does a channel lookup during setup,
even though we haven't yet programmed in a channel. Sigh.
Tested:
* WB225 (AR9485) + bluetooth
work in FreeBSD.
This is still heavily a work in progress but I'd rather it start
shipping in -HEAD sooner rather than later.
This doesn't (yet) link it into the build system either for a static
kernel or as a module; that will come later (after many, many make universe
tests.)