This patch configures TLS for OVN to use the local CA cert on the
controller. The compute nodes request certificates to be provided by the
CA cert and will use those certificates to configure local controller
connections to the OVN SB database via TLS. The client certificates are
validated against the control nodes CA.
Local connections on the control node continue to use the local unix
socket, which should be considered to be secure since it does not egress
the node.
Change-Id: Iacf5d5637c3a093bd80879c2ebb58efb16b52e66