helpers: add helpers to work with workqueue subsystem.

Sometimes we come across issues where due to high system load, one
or more work items could not get timely executed and this in turn
caused other issues. Besides such issues we also come across problems
arising due to racy execution of work items and several other issues
involving workers, workqueues or individual work items.

Having helpers for workqueue subsystem can help in debugging such issues.

Signed-off-by: Imran Khan <[email protected]>

Author: imran-kn