Only enable auto-enabled zones on hotplug events
Let hotplug handlers return a status code

After a port has been hotplugged, we will walk through all
port configuration files and check if the device matches.
The hooks must now return whether they have handled the event
so that we can stop searching or not.
batman-adv: Disable hotplug hook

Doesn't work as expected right now and needs to
be rewritten later.
batman-adv-port: Initialize PHY variable