blk-mq: add a new queue flag to quiesce/unquiesce queue

hulk inclusion
category: bugfix
bugzilla: 173974
CVE: NA
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Queue will be quiesced if the old or the new flag is set, and the
queue will be unqiesced if both flags is cleared.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>