Enable ovs-vswitchd and ovsdb-server for rally

The ovs-vswitchd and ovsdb-server services were missing in the rally
definition. Usually the jobs inherts from our base class which enables
them but rally has a different job parent.

Change-Id: Icd26d2fbdb71480184f3814f07e82025f7ddd963
Signed-off-by: Lucas Alvares Gomes <lucasagomes@gmail.com>

zuul.d/networking-ovn-jobs.yaml

@@ -278,6 +278,8 @@
       devstack_services:
         ovn-northd: true
         ovn-controller: true
+        ovs-vswitchd: true
+        ovsdb-server: true
         networking-ovn-metadata-agent: true
         br-ex-tcpdump: true
         br-int-flows: true