Add neutron::config to network control classgroups

Most class groups now include the <service>::config class.
These generic classes make it possible to add arbitrary
configuration for items that don'thave full class params
either because such haven't been added yet or because they're
seldom used.  However we don't currently include the neutron::config
class in the classgroups related to network controllers.  This
patch corrects the oversight.

Change-Id: I82fef066cf7052220fcfc5f3f2a6f1fb8f47bfb3
Closes-Bug: #1358533