bug 7202 upon node reboot hwvtep op ds is missing

bug 7202 upon node reboot hwvtep op ds is missing

When the cluster is rebooted hwvtep operational datastore is not populated
for the existing clients.
Existing clients keep retrying , the moment 6640 port is up they establish
connection.
But by that time hwtep bundle is not up.
Eventually when the bundle is up it is only notified of future clients
only and not the already existing clients.

Change-Id: Ic816aea61c43000d7c8fbf14e51e0bcc5661664e
Signed-off-by: K.V Suneelu Verma <k.v.suneelu.verma@ericsson.com>