Add systemd dependency to openvswitch to ovn-controller

Ovn controller need openvswitch to be running properly. This
patch adds the required depends_on so paunch can add the dependency to
the systemd service file.

Closes-bug: #1921097
Change-Id: I2e54771f0a01d22ce95530bef146ea368189db24

deployment/ovn/ovn-controller-container-puppet.yaml

@@ -256,6 +256,8 @@ outputs:
             privileged: true
             user: root
             restart: always
+            depends_on:
+              - openvswitch.service
             healthcheck:
               test:
                 list_join: