mac80211: add a few upstream fixes

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

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@39846 3c298f89-4303-0410-b956-a3cf2f4a3e73
ath9k: further reduce false baseband hang detects on older chips

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

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@39847 3c298f89-4303-0410-b956-a3cf2f4a3e73