The workqueue "wq" is used for handling battery related tasks.

It has a single work item viz &mb->update and hence it doesn't require
execution ordering. Hence, alloc_workqueue has been used to replace the
deprecated create_singlethread_workqueue instance.

The WQ_MEM_RECLAIM flag has been set to ensure forward progress under
memory pressure.

Since there is a single work item, explicit concurrency
limit is unnecessary here.
Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>