Switch neutron-tempest-plugin-api job to be ML2/OVS

It will give us more API tests coverage as we don't need to e.g.
skip logging tests, even when Devstack will be switched to the ML2/OVN
backend.
It also enables deploying Neutron with uwsgi again, as with ML2/OVS
backend it isn't broken.

Change-Id: I90f3c430504677a42e98230b84ea87f863c1331b
Closes: #1928345

zuul.d/master_jobs.yaml

@@ -86,11 +86,25 @@
         - ipv6_metadata
       tempest_test_regex: ^neutron_tempest_plugin\.api
       devstack_services:
+        # Disable OVN services
+        br-ex-tcpdump: false
+        br-int-flows: false
+        ovn-controller: false
+        ovn-northd: false
+        ovs-vswitchd: false
+        ovsdb-server: false
+        q-ovn-metadata-agent: false
+        # Neutron services
+        q-agt: true
+        q-dhcp: true
+        q-l3: true
+        q-meta: true
+        q-metering: true
         neutron-log: true
       devstack_localrc:
-        # TODO(lucasagomes): Re-enable MOD_WSGI after
-        # https://bugs.launchpad.net/neutron/+bug/1912359 is implemented
-        NEUTRON_DEPLOY_MOD_WSGI: false
+        Q_AGENT: openvswitch
+        Q_ML2_TENANT_NETWORK_TYPE: vxlan
+        Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch
       devstack_local_conf:
         post-config:
           # NOTE(slaweq): We can get rid of this hardcoded absolute path when