Update NVP plugin name for Neutron.

Module nicira_nvp_plugin no longer exists and it can be removed from
the plugin name.

Supports blueprint nicira_nvp_plugin

Change-Id: I19bdbb3c9e7aa05f672789766f3c0fd528682f03
Merge "Update NVP plugin name for Neutron."
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp