mac80211: backport a few upstream fixes

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

Backport of r37653

git-svn-id: svn://svn.openwrt.org/openwrt/branches/attitude_adjustment@37728 3c298f89-4303-0410-b956-a3cf2f4a3e73
AA: ath9k: add an updated version of the tx queueing rework, refresh patches

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/branches/attitude_adjustment@37729 3c298f89-4303-0410-b956-a3cf2f4a3e73