nvme: Quirks for PM1725 controllers

nvme: Quirks for PM1725 controllers

BugLink: http://bugs.launchpad.net/bugs/1704435
PM1725 controllers have a couple of quirks that need to be handled in
the driver:

 - I/O queue depth must be limited to 64 entries on controllers that do
   not report MQES.

 - The host interface registers go offline briefly while resetting the
   chip. Thus a delay is needed before checking whether the controller
   is ready.

Note that the admin queue depth is also limited to 64 on older versions
of this board. Since our NVME_AQ_DEPTH is now 32 that is no longer an
issue.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
(backported from d554b5e1ca64d23e4f839e6531490fee8479fbaf)
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>