drm/i915/selftests: Align igt_spinner_create_request with hangcheck

Align igt_spinner_create_request with the hang_create_request
implementation in selftest_hangcheck.c.
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Acked-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230815165345.964068-2-jonathan.cavitt@intel.com

drivers/gpu/drm/i915/selftests/igt_spinner.c

@@ -179,6 +179,9 @@ igt_spinner_create_request(struct igt_spinner *spin,
 
 	*batch++ = arbitration_command;
 
+	memset32(batch, MI_NOOP, 128);
+	batch += 128;
+
 	if (GRAPHICS_VER(rq->i915) >= 8)
 		*batch++ = MI_BATCH_BUFFER_START | BIT(8) | 1;
 	else if (IS_HASWELL(rq->i915))