treewide: nuke DRIVER_11W_SUPPORT

treewide: nuke DRIVER_11W_SUPPORT

As of hostapd upstream commit 7d2ed8ba "Remove CONFIG_IEEE80211W build parameter"
https://w1.fi/cgit/hostap/commit?id=7d2ed8bae86a31dd2df45c24b3f7281d55315482
802.11w feature is always enabled in the build time.

It doesn't make sense to opt-in 802.11w per driver as hostapd will always
be compiled with this feature enabled.

As suggested by Hauke Mehrtens, for now keep 11w enabled in build_features.h
for compatibility reasons. This option will be dropped when LuCI is adjusted.

Signed-off-by: Dobroslaw Kijowski <dobo90@gmail.com>