mac80211/minstrel: use the new rate control API

Pass the rate selection table to mac80211 from minstrel_update_stats.
Only rates for sample attempts are set in info->control.rates, with deferred
sampling, only the second slot gets changed.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>