With commit baef191d1f5b26119e098d4ae72fb032f5a79d0e, we have
defined aliases for different version of vmware_nsx plugins. Now,
if we don't provide alias during devstack setup, neutron failed
to come up with the following error
"NoMatches: No 'neutron.core_plugins' driver found, looking for
'vmware_nsx.plugin.NsxV3Plugin'"
This patch changes Q_PLUGIN_CLASS to vmware_nsx aliases. So that
the core_plugins in neutron conf will use that to load.
Change-Id: Ibaa1caf4dc7ad14d5f7e3e43ca5173e6474f9451
418c773e14