nvme: prepare for pairing quiescing and unquiescing

mainline inclusion
from mainline-v5.16
commit ebc9b952
category: bugfix
bugzilla: 182378 https://gitee.com/openeuler/kernel/issues/I4DDEL

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ebc9b95260151d966728cf0063b3b4e465f934d9



---------------------------

Add two helpers so that we can prepare for pairing quiescing and
unquiescing which will be done in next patch.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211014081710.1871747-4-ming.lei@redhat.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>

conflict: commit d17e66aa ("nvme: use set_capacity_and_notify in
nvme_set_queue_dying") is not backported.
 - drivers/nvme/host/core.c
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>

Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>