nvme-pci: qdepth 1 quirk

Another device has been reported to be unreliable if we have more than
one outstanding command. In this new case, data corruption may occur.
Since we have two devices now needing this quirky behavior, make a
generic quirk flag.

The same Apple quirk is clearly not "temporary", so update the comment
while moving it.

Link: https://lore.kernel.org/linux-nvme/191d810a4e3.fcc6066c765804.973611676137075390@collabora.com/


Reported-by: Robert Beckett <bob.beckett@collabora.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>