MFC r344990:
Fix ieee80211_radiotap(9) usage in wireless drivers:

- Alignment issues:
* Add missing __packed attributes + padding across all drivers; in
most places there was an assumption that padding will be always
minimally suitable; in few places - e.g., in urtw(4) / rtwn(4) -
padding was just missing.
* Add __aligned(8) attribute for all Rx radiotap headers since they can
contain 64-bit TSF timestamp; it cannot appear in Tx radiotap headers, so
just drop the attribute here. Refresh ieee80211_radiotap(9) man page
accordingly.

- Since net80211 automatically updates channel frequency / flags in
ieee80211_radiotap_chan_change() drop duplicate setup for these fields
in drivers.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

otus: switch to ieee80211_add_channel_list_*()

- Use device's channel list instead of default one
(from ieee80211_init_channels()).
- Sort channels (ieee80211_add_channel_list_* requirement).
- Add ic_getradiocaps() method.

Added channels:
2GHz band: 12, 13 and 14.
5GHz band: 34, 38, 42, 46 and 165.

Reviewed by: adrian
Differential Revision: https://reviews.freebsd.org/D6145

otus(4) - add flags for RX filter, configuration and sniffer.

Obtained from: Linux carl9170

net80211: WME callback cleanup in various drivers

Since r288350, ic_wme_task() is called via ieee80211_runtask(),
so, any additional deferring from the driver side is not needed.

Approved by: adrian (mentor)
Differential Revision: https://reviews.freebsd.org/D4072

otus(4) - demagicify register names.

Obtained from: Linux carl9170 hw.h

net80211 drivers: eliminate any references to sc_rxtap_len/sc_txtap_len (never used here)

Submitted by: <s3erios@gmail.com>
Differential Revision: https://reviews.freebsd.org/D3776

Declare odata as a pointer type instead of a pointer to pointer.

Reviewed by: adrian

if_otus fixes; add fast-frames support.

Fast-frames:

* include opt_wlan.h ; tsk to not doing it earlier;
* add a tx pending tracking counter for seeing how deep
the hardware TX queue is;
* add the frame aging code from if_ath;
* add fast-frames capability to the driver setup.

Bugs:

* free the buffers (and node references) before
detaching net80211 state. This prevents a use-after-free in
the node free path where we've destroyed net80211 underneath it.

Track the command response code buffer size and verify it in the
receive path.

Add an initial driver for the AR9170 series draft-11n hardware from
Atheros.

Thanks to OpenBSD for providing a driver based on the original
Atheros open source driver circa 2008. This uses the early, pre-carl9170
atheros provided firmware.

It only supports 11bg at the moment. I've not tested it with 11a
(and so the TX rate control logic may be slightly wrong!) so if
you do have the dual-band version of this hardware please do let me know.

Tested:

* AR9170, TP-Link WN821N 2GHz.

TODO:

* Hook this up to a non-module build.