so remove irq requesting/releasing into _open and _close so
that while the device is _up we will never touch the irq's. This fixes
the double free irq bug that people saw.

To make sure that the watchdog task doesn't cause another race we let
it run as a non-scheduled task.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>

(2-,›"x