[lib80211] /net/ieee80211/ was removed in new kernel versions.

This adds lib80211 for new kernel versions and make ipw2x00 and hostap driver depend on it.


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@15777 3c298f89-4303-0410-b956-a3cf2f4a3e73