Fix cfg_group not found in dvs plugin

commit 61c19f3e9c9314811ea9695690391ef2a018ce6e uses cfg_group to find
corresponding plugin's metadata mode info. But it loses the cfg_group
defination on dvs plugin.

Co-Authored-by: Giridhar Jayavelu <gjayavelu@vmware.com>

Change-Id: Ice19b64d0bfcb663bd882923c35566a4916c06d5

vmware_nsx/dvs/dvs_utils.py

@@ -44,6 +44,10 @@ dvs_opts = [
                     'socket error, etc.'),
     cfg.StrOpt('dvs_name',
                help='The name of the preconfigured DVS.'),
+    cfg.StrOpt('metadata_mode',
+               help=_("This value should not be set. It is just required for "
+                      "ensuring that the DVS plugin works with the generic "
+                      "NSX metadata code")),
 ]
 
 CONF = cfg.CONF

vmware_nsx/plugins/dvs/plugin.py

@@ -81,6 +81,7 @@ class NsxDvsV2(addr_pair_db.AllowedAddressPairsMixin,
         LOG.debug('Driver support: DVS: %s' % dvs_utils.dvs_is_enabled())
         neutron_extensions.append_api_extensions_path(
             [vmware_nsx.NSX_EXT_PATH])
+        self.cfg_group = 'dvs'  # group name for dvs section in nsx.ini
         self._dvs = dvs.DvsManager()
 
         # Common driver code