mac80211: extend AQL aggregation estimation to HE and fix unit mismatch

mac80211: extend AQL aggregation estimation to HE and fix unit mismatch

The unit of the return value of ieee80211_get_rate_duration is nanoseconds, not
microseconds. Adjust the duration checks to account for that.
For higher data rates, allow larger estimated aggregation sizes, and add some
values for HE as well, which can use much larger aggregates.
Since small packets with high data rates can now lead to duration values too
small for info->tx_time_est, return a minimum of 4us.

Fixes: f01cfbaf9b29 ("mac80211: improve AQL aggregation estimation for low data rates")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20200915085945.3782-1-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>