Fails to get DPDK feature status.
Fails to get DPDK feature status.

This change is to get dpdk feature status for a role
when using docker service neutron-ovs-dpdk-agent.yaml file.
DPDK derive params workflow is not invoked and derived
parameters for dpdk role when using docker service
neutron-ovs-dpdk-agent.yaml file for deployment.
_get_role_info workflow is failed to get dpdk feature enabled
status for dpdk role.

Change-Id: I3e878e5dacf8e78710c892309b0d064506ec7345
Closes-Bug: #1759296

openstack/tripleo-common,openstack/tripleo-common