Add extra_args for tempest image

Change-Id: Ife44623b358587a6fe232580d21beca22555858e
diff --git a/tcp_tests/fixtures/runtest_fixtures.py b/tcp_tests/fixtures/runtest_fixtures.py
index 53342ae..225b005 100644
--- a/tcp_tests/fixtures/runtest_fixtures.py
+++ b/tcp_tests/fixtures/runtest_fixtures.py
@@ -24,6 +24,7 @@
     """
     tempest_threads = settings.TEMPEST_THREADS
     tempest_pattern = settings.TEMPEST_PATTERN
+    tempest_extra_args = settings.TEMPEST_EXTRA_ARGS
     cluster_name = settings.LAB_CONFIG_NAME
     domain_name = settings.DOMAIN_NAME
     runtest = RuntestManager(
@@ -31,6 +32,7 @@
         underlay_actions, salt_actions,
         cluster_name=cluster_name,
         domain_name=domain_name,
+        tempest_extra_args=tempest_extra_args,
         tempest_threads=tempest_threads,
         tempest_pattern=tempest_pattern)
     return runtest