This patch removes the devstack/lib/ovs module and update the scripts to
use the ovs_source module from DevStack instead.
Depends-On: https://review.opendev.org/c/openstack/devstack/+/791085
Change-Id: I65fe53ee753ac68340f7d4d928643d3d8e5c8694
Signed-off-by: Lucas Alvares Gomes <lucasagomes@gmail.com>