Also - allow driver specific bits to be added, rather than just net80211.
This still isn't as useful as it should be by default; it needs to
be a standalone struct/instance so it can be done before net80211
registration occurs, and it can log per-device items.
But, it's getting there.
This is destined to be a lightweight and optional set of ALQ
probes for debugging events which are just impossible to debug
with printf/log (eg packet TX/RX handling; AMPDU handling.)
The probes and operations themselves will appear in subsequent
commits.
