bootdevice: Gather LCHS from all relevant devices

Relevant devices are:
    * ide-hd (and ide-cd, ide-drive)
    * scsi-hd (and scsi-cd, scsi-disk, scsi-block)
    * virtio-blk-pci

We do not call del_boot_device_lchs() for ide-* since we don't need to -
IDE block devices do not support unplugging.

Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com>
Reviewed-by: Arbel Moshe <arbel.moshe@oracle.com>
Signed-off-by: Sam Eiderman <shmuel.eiderman@oracle.com>
Signed-off-by: Sam Eiderman <sameid@google.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>