Move DPDK-related functions to DPDKTest

The previous change

268b429

did not move the rest of the functions required to actually run the
test case.

(cherry picked from commit 787415a)

zaza/openstack/charm_tests/ovn/tests.py

@@ -197,6 +197,10 @@ def test_wrong_bridge_config(self):
             self.test_config[
                 'target_deploy_status'] = stored_target_deploy_status
 
+
+class DPDKTest(test_utils.BaseCharmTest):
+    """DPDK-related tests."""
+
     def _openvswitch_switch_dpdk_installed(self):
         """Assert that the openvswitch-switch-dpdk package is installed.
 
@@ -294,10 +298,6 @@ def _dpdk_pre_post_flight_check(self):
                 msg='OVS unexpectedly has DPDK initialized'):
             self._ovs_dpdk_initialized()
 
-
-class DPDKTest(test_utils.BaseCharmTest):
-    """DPDK-related tests."""
-
     def test_enable_dpdk(self):
         """Confirm that transitioning to/from DPDK works."""
         logging.info('Pre-flight check')