Add $DISTRO_PATH to find release file for centosci
Add $DISTRO_PATH to find release file for centosci

The release files in
tripleo-quickstart/tree/master/config/release/centosci
had a flat dir structure and did not allow for
releases of the same name on different distros.

This review (along with
https://review.opendev.org/c/openstack/tripleo-quickstart/+/828171)
references release files distro path.

Change-Id: I6eb8e52ee32b3b39a83653a23b8de06b6ace8bf8

rdo-infra/ci-config,redhat-openstack/rdo-infra,rdo-infra/ci-config,redhat-openstack/rdo-infra,redhat-openstack/rdo-infra,redhat-openstack/rdo-infra,rdo-infra/ci-config,rdo-infra/ci-config