Env files for ODL deployments

Env files for ODL deployments

This patch adds env files for SRIOV, OVS-DPDK, L2GW, BGPVPN
and SFC deployments with ODL.

These files contain configs not present in basic ODL deployment
env file. While deploying, these need to be used along the basic
deployment env file like

openstack overcloud deploy \
 -e environments/services-docker/neutron-opendaylight.yaml \
 -e environments/services-docker/neutron-opendaylight-dpdk.yaml

and

openstack overcloud deploy \
 -e environments/services-docker/neutron-opendaylight.yaml \
 -e environments/services-docker/neutron-opendaylight-sriov.yaml

and so forth for all other deployments.

Closes-Bug: 1722881

Change-Id: I2b70d3f4518e0c014cf37f7fecd92f69989f0860
(cherry picked from commit e0c89d6593dadd9bf6ba9fa6f618e7c44ec7aa2e)