In order for DVR to work on VLAN tenant networks we need to configure
external_ids:ovn-chassis-mac-mappings with per node generated MAC [1]
on computes [1].

[1]: https://github.com/ovn-org/ovn/commit/1fed74cfc1a1e3b29cf86eab2e96048813019b57



Co-Authored-By: Bartosz Bezak <bartosz@stackhpc.com>

Depends-On: https://review.opendev.org/c/openstack/neutron/+/782250
Change-Id: I3a3ccde5b9ef2afb4c3e9206f13827687880cb57