This patch removes the mentioned drivers from ironic code tree.
Per our third-party drivers policy they are unsupported,
and there is no existing plan to have third-party CI for them.
Nevertheless, if anybody still needs them, they are available in
ironic-staging-drivers repo.
Change-Id: I1219892bbc1b814d80b62c8ec89b90819071870f
Related-Bug: #1640533