mei: set device client to the disconnected state upon suspend.

This fixes regression introduced by
commit 8d52af67 ("mei: speed up the power down flow")

In mei_cldev_disable during device power down flow, such as
suspend or system power off, it jumps over disconnecting function
to speed up the power down process, however, because the client is
unlinked from the file_list (mei_cl_unlink) mei_cl_set_disconnected
is not called from mei_cl_all_disconnect leaving resource leaking.
The most visible is reference counter on underlying HW module is
not decreased preventing to remove modules after suspend/resume cycles.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Fixes: 8d52af67 ("mei: speed up the power down flow")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>