mac80211: support rate-control based TX ratestats

The rate control algorithms typically already capture (some)
rate statistics (minstrel fully, for example) so adding more
to mac80211 isn't very useful.

Add support for the rate control reporting TX ratestats by
simply passing through the start/dump/stop calls to it.

If rate control doesn't have support, then don't allow the
driver to support ratestats. This ensure that full ratestats
support is always there if it is supported at all. If any
driver that doesn't have mac80211-based rate control will
want to support it we'll add the same as a driver operation
and adjust the code accordingly.

Automatically set the feature flag if the conditions are right.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
5 files changed