Define quantum-plugin-ovs package resource for ovs agent and plugin.

deploying ovs agent on rhel 6.4 fails with a Could not find resource
'Package[quantum-plugin-ovs]' for relationship on 'Quantum_plugin_ovs[OVS/local_ip]' on node.
This fix only defined the resource if not defined already.

Change-Id: Iedf8a607915f65b7a8cf7af99749b9b65cba7bd9
Merge "Define quantum-plugin-ovs package resource for ovs agent and plugin."