Replace the deprecated create_singlethread_workqueue() with
alloc_ordered_workqueue() with WQ_MEM_RECLAIM. This is the identity
conversion.

It's not recommended to stall it from memory pressure. Hence,
WQ_MEM_RECLAIM has been set to ensure forward progress under memory
pressure.
Signed-off-by: NBhaktipriya Shridhar <bhaktipriya96@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20160813164124.GA9077@KaryakshetraSigned-off-by: NBorislav Petkov <bp@suse.de>

Hide the EDAC workqueue pointer in a separate compilation unit and add
accessors for the workqueue manipulations needed.

Remove edac_pci_reset_delay_period() which wasn't used by anything. It
seems it got added without a user with

  91b99041 ("drivers/edac: updated PCI monitoring")
Signed-off-by: NBorislav Petkov <bp@suse.de>