ath9k: add a fix for ANI related stability issues

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

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@41028 3c298f89-4303-0410-b956-a3cf2f4a3e73
ath9k: add a fix for rx overrun processing

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

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@41029 3c298f89-4303-0410-b956-a3cf2f4a3e73
Merge remote-tracking branch 'upstream/master'