drm/i915: Report request restarts for both execlists/guc

drm/i915: Report request restarts for both execlists/guc

As we now share the execlist_port[] tracking for both execlists/guc, we
can reset the inflight count on both and report which requests are being
restarted.

Suggested-by: Michel Thierry <michel.thierry@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170425103835.31871-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>