nvme/pci: Don't set reserved SQ create flags

The QPRIO field is only valid if weighted round robin arbitration is used,
and this driver doesn't enable that controller configuration option.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>