The ESP SCSI controllers (NCR53C90, DC390, AM53C974) have the same
requirement as the LSI Logic controller for each disk to be set via
the scsi-id=NNN property, not the lun=NNN property.
Switching the code to use an enum will force authors to pay attention
to this difference when adding future SCSI controllers.
Reviewed-by: Laine Stump <laine@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
