drm/i915/guc: Disable rpm wakeref asserts in GuC irq handler

We're seeing "RPM wakelock ref not held during HW access" warning
otherwise. Since IRQs are synced for runtime suspend we can just disable
the wakeref asserts.

Reported-by: Marta Löfstedt <marta.lofstedt@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105710


Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180714173703.7894-1-chris@chris-wilson.co.uk


Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>