Add OVN chassis macs to hieradata

Add the tempalte in tripleo-ansible to the list of
hieradata_templates in common/hiera-steps-tasks.yaml

Depends-On: https://review.opendev.org/733719
Related-Bug: #1881593
Change-Id: I0a57374c5b58f5953b079b6690ecc77887ec8751

common/hiera-steps-tasks.yaml

@@ -24,6 +24,7 @@
       - service_configs
       - extraconfig
       - role_extraconfig
+      - ovn_chassis_mac_map
 - name: Ensure ansible_managed hieradata file exists
   include_role:
     name: tripleo_hieradata