Since we run the watchdog periodically, which might take a while and
potentially monopolize the system default workqueue, create our own
separate work queue. This also helps reduce and stabilize latency
between scheduling the work in our interrupt and actually performing
the work. Still use a timer for the regular scheduled interval but
queue the work onto its own work queue.

It seemed overkill to create a single workqueue per interface, so we
just spawn a single work queue for all interfaces upon driver load. For
this reason, use a multi-threaded workqueue with one thread per
processor, rather than single threaded queue.
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Acked-by: NMatthew Vick <matthew.vick@intel.com>
Tested-by: NKrishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>