Minor change to neutron controller script

Moves nova related parameter to its respective location, does not
have any functional impacts. Also swaps auth_protocol with auth_port
to keep it in sync with install guides. Classifies ml2 sections by
adding comments.

Change-Id: I7739451f2959099e2b9485b2e0adbe721a9edfd7
Merge "Minor change to neutron controller script"