ibmvscsi: display default value for max_id, max_lun and max_channel.

As devices with values greater than that are silently ignored,
this gives some hints to the sys admin to know why he doesn't see
his devices...

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>