Legacy elements deploy-tgtadm, deploy-targetcli, and deploy-baremetal
have not seen use in ages. Another element seems to date back to this,
deploy-kexec, but appears to see no actual use as the underlying methods
leveraged by these elements were long moved away from. iSCSI based
deployment being the last, and even then it required the
ironic-python-agent.
Change-Id: Ib5b3a7690c35d6859e2e0fdac2326dcd16c051d3