Delete OVN MAC addr ports prior to deleting stack

With I6ce29d2908e76044c55eb96d0d3779fe67ba9169 the
OVN MAC address ports created as part of deploy-steps
playbook run won't be cleaned up on 'overcloud delete'

This change fixes that by running the ansible module
tripleo_ovn_mac_addresses without specifying a list
of services.

Implements: blueprint network-data-v2-port
Depends-On: https://review.opendev.org/782892
Change-Id: Id08cb1f907ba9ea9fb1bf1865d8a6491b463c44d

.ansible-lint

@@ -68,3 +68,4 @@ mock_modules:
     - tripleo_overcloud_network_vip_extract
     - tripleo_overcloud_network_vip_provision
     - tripleo_overcloud_network_vip_populate_environment
+    - tripleo_ovn_mac_addresses

tripleo_ansible/ansible_plugins/modules/tripleo_ovn_mac_addresses.py

@@ -228,7 +228,7 @@ def run_module():
     stack = module.params.get('stack_name', 'overcloud')
     role_name = module.params['role_name']
     bridge_mappings = module.params['ovn_bridge_mappings']
-    servers = module.params['server_resource_names']
+    servers = module.params.get('server_resource_names') or []
     playbook_dir = module.params['playbook_dir']
     concurrency = module.params.get('concurrency', 0)
     static_mappings = module.params.get(
@@ -241,8 +241,9 @@ def run_module():
             _, conn = openstack_cloud_from_module(module)
 
             net_id = create_ovn_mac_address_network(result, conn)
-            tags = ['tripleo_stack_name={}'.format(stack),
-                    'tripleo_role={}'.format(role_name)]
+            tags = ['tripleo_stack_name={}'.format(stack)]
+            if role_name:
+                tags.append('tripleo_role={}'.format(role_name))
 
             # no limit on concurrency, create a worker for every server
             if concurrency < 1:

tripleo_ansible/playbooks/cli-overcloud-delete.yaml

@@ -34,6 +34,9 @@
       tripleo_service_vip:
         stack_name: "{{ stack_name }}"
         state: absent
+    - name: Delete OVN MAC Address ports
+      tripleo_ovn_mac_addresses:
+        stack: "{{ stack_name }}"
     - name: Delete heat stack
       openstack.cloud.stack:
         name: "{{ stack_name }}"