Update upstream modules

This updates OpenWRT and rebases our patches.

Furthermore, the mac80211 module is removed as currently the Attitude Adjustment
main repo has a newer version (and some fixes that aren't in the backport repo).

Also, update odhcp6c from Barrier Breaker.
Update netifd from Barrier Breaker

This allows us to drop our config mode patch.
netifd: fix proto none crash
Merge branch 'master' of github.com:freifunk-gluon/gluon