libsas handles:
1/ limiting ata scanning to lun0
2/ changes to /sys/block/<sdX>/device/queue_depth for ata devices

libata handles turning off ncq globally via kernel command line
(libata.force=noncq) or sysfs (echo 1 >
/sys/block/<sdX>/device/queue_depth).  A lldd specific compile option is
not necessary.

Cc: Jack Wang <jack_wang@usish.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>