cifs: add sysfs support to deliver uevent to userspace

cifs: add sysfs support to deliver uevent to userspace

We need more detailed SMB status in userspace to help
users to be aware of NAS status, including failure.

Bug 200396506

Change-Id: I50e1a2c7a4b83b6b3ad006f4f6b34c4080f28fb6
Signed-off-by: Jean Huang <jeanh@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1679077
(cherry picked from commit dcd8b224377915bcc3112c9704f43965e283518b)
Reviewed-on: https://git-master.nvidia.com/r/1850588
GVS: Gerrit_Virtual_Submit
Reviewed-by: Patrick Horng <phorng@nvidia.com>
Tested-by: Patrick Horng <phorng@nvidia.com>
Reviewed-by: Vinayak Pane <vpane@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>