mac80211: revert a faulty upstream change which is causing channel 12 to be enabled for US regdomain

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

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@41298 3c298f89-4303-0410-b956-a3cf2f4a3e73
iw: update to 3.15

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

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@41299 3c298f89-4303-0410-b956-a3cf2f4a3e73
mac80211: disable greenfield by default

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

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@41300 3c298f89-4303-0410-b956-a3cf2f4a3e73