ath9k: add support for IEEE80211_TX_CTL_PS_RESPONSE

Use the UAPSD hardware queue to get PS-Poll responses out as fast as
possible and without backoff.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
3 files changed