Networking-SFC is a neutron big-tent project support Service Function
Chaining in Neutron.

* Rename the image from neutron-networking-sfc-agent to
  neutron-sfc-agent.
* Add networking-sfc role in playbooks.

Co-Authored-by: Jeffrey Zhang <zhang.lei.fly@gmail.com>
Change-Id: I1f99650eed85f59929d4ab6b2226603c54f29577
Implements: blueprint enable-networking-sfc-support