drm/xe: Introduce fault injection for guc mmio send/recv.

drm/xe: Introduce fault injection for guc mmio send/recv.

Fault can be injected with below steps.

FAILTYPE=fail_function
FAILFUNC=xe_guc_mmio_send_recv

echo > /sys/kernel/debug/$FAILTYPE/inject
echo $FAILFUNC > /sys/kernel/debug/$FAILTYPE/inject
printf %#x -5 > /sys/kernel/debug/$FAILTYPE/$FAILFUNC/retval

echo N > /sys/kernel/debug/$FAILTYPE/task-filter
echo 10 > /sys/kernel/debug/$FAILTYPE/probability
echo 0 > /sys/kernel/debug/$FAILTYPE/interval
echo -1 > /sys/kernel/debug/$FAILTYPE/times
echo 0 > /sys/kernel/debug/$FAILTYPE/space
echo 1 > /sys/kernel/debug/$FAILTYPE/verbose

Signed-off-by: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Michał Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://lore.kernel.org/r/20250403120641.7258-2-satyanarayana.k.v.p@intel.com