LinuxKPI: 80211 (+net80211): update and cleanup headers

Fix types for various struct fields (initially added as int).

Move structs and inline functions logically together, e.g., for wowlan.
Add more skeleton functions and #defines needed for iwlwifi d3.c
in the future.

Add struct ieee80211_vht_cap (without "_ie") to net80211 and remove
duplicate definitions in LinuxKPI headers now using net80211 structs.
For now leave ieee80211_ie_vhtcap in net80211. I am not sure yet if we
actually need it as such. That'll be cleaned up with more VHT updates
in net80211 in the future.

No functional changes in currently compiled code intended.

Try to implement ieee80211_action_contains_tpc() as I ran into it with
an older iwlwifi chipset. This depends on c994352a8841eb453.

Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks