nvme: add quirk to force medium priority for SQ creation

Some P3100 drives have a bug where they think WRRU (weighted round robin)
is always enabled, even though the host doesn't set it. Since they think
it's enabled, they also look at the submission queue creation priority. We
used to set that to MEDIUM by default, but that was removed in commit
81c1cd98. This causes various issues on that drive. Add a quirk to
still set MEDIUM priority for that controller.

Fixes: 81c1cd98

 ("nvme/pci: Don't set reserved SQ create flags")
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Keith Busch <keith.busch@intel.com>