nvme: expose active quirks in sysfs

nvme: expose active quirks in sysfs

Currently, there is no straightforward way for a user to inspect
which quirks are active for a given device from userspace.

Add a new "quirks" sysfs attribute to the nvme controller device.

Reading this file will display a human-readable list
of all active quirks, with each quirk name on a new line.
If no quirks are active, it will display "none".

Tested-by: John Meneghini <jmeneghi@redhat.com>
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>