nvme: copy MTFA field from identify controller

mainline inclusion
from mainline-5.2-rc2
commit 2d466c7a
category: bugfix
bugzilla: 167363
CVE: NA

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

We use the controller's reported maximum firmware activation time as our
timeout before resetting a controller for a failed activation notice,
but this value was never being read so we could only use the default
timeout. Copy the Identify Controller MTFA field to the corresponding
nvme_ctrl's mtfa field.

Fixes: b6dccf7f (“nvme: add support for FW activation without reset”).
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Minwoo Im <minwoo.im@samsung.com>
Signed-off-by: Laine Walker-Avina <laine.walker-avina@intel.com>
[changelog, fix endian]
Signed-off-by: Keith Busch <keith.busch@intel.com>

Conflicts:
	drivers/nvme/host/core.c
	[ Cleanup 43e2d08d("nvme: avoid double dereference to
	  convert le to cpu") is not applied. ]

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>