cleanup the user data disk if node.set_provision_state deleted

deploy the baremetal, ironic will cleanup the baremetal's first harddisk before 'dd' the disk image to it.

baremetal will have other harddisks, like '/dev/sda' and '/dev/sdb', the end-user will use /dev/sdb to save data. when ironic set_provision_state this node deleted, this node will be teared down, '/dev/sda' and '/dev/sdb' not be cleaned. if this node deploy again for the other use, he will get the all the local disk data except '/dev/sda'.

this bp cleanup all of the local disk when set-provision-state node deleted.