iw: sync nl80211.h

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

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@42688 3c298f89-4303-0410-b956-a3cf2f4a3e73
iw: add support for dynamic distance selection (supported by ath9k now)

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

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@42689 3c298f89-4303-0410-b956-a3cf2f4a3e73