baremetal: drop 'prov_mac_address' column

bm_nodes.prov_mac_address is no longer used. So drop it.

Change-Id: I3c7294da8f62581aba8c948171cb02f80cf054ef
Merge "baremetal: drop 'prov_mac_address' column"
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp