Add neutron-tempest-plugin-fwaas-ovn job

The existing job is now renamed from "neutron-tempest-plugin-fwaas" to
"neutron-tempest-plugin-fwaas-openvswitch" and there is also new job,
based on the ML2/OVN backend added as well.

Change-Id: I7026750882e59ce2b3b9e26d840c62f208be5945
diff --git a/zuul.d/zed_jobs.yaml b/zuul.d/zed_jobs.yaml
index f99ff42..f936b8c 100644
--- a/zuul.d/zed_jobs.yaml
+++ b/zuul.d/zed_jobs.yaml
@@ -288,7 +288,7 @@
 
 - job:
     name: neutron-tempest-plugin-fwaas-zed
-    parent: neutron-tempest-plugin-fwaas
+    parent: neutron-tempest-plugin-fwaas-openvswitch
     nodeset: openstack-single-node-focal
     override-checkout: unmaintained/zed
     required-projects: *required-projects-zed