Merge tag 'nvme-5.13-2021-04-22' of git://git.infradead.org/nvme into for-5.13/drivers

Pull NVMe updates from Christoph:

"- add support for a per-namespace character device (Minwoo Im)
 - various KATO fixes and cleanups (Hou Pu, Hannes Reinecke)
 - APST fix and cleanup"

* tag 'nvme-5.13-2021-04-22' of git://git.infradead.org/nvme:
  nvme: introduce generic per-namespace chardev
  nvme: cleanup nvme_configure_apst
  nvme: do not try to reconfigure APST when the controller is not live
  nvme: add 'kato' sysfs attribute
  nvme: sanitize KATO setting
  nvmet: avoid queuing keep-alive timer if it is disabled