drm/tegra: submit: Add missing pm_runtime_mark_last_busy()

Runtime PM auto-suspension doesn't work without pm_runtime_mark_last_busy(),
add it.

Cc: <stable@vger.kernel.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/submit.c

@@ -504,8 +504,10 @@ static void release_job(struct host1x_job *job)
 	kfree(job_data->used_mappings);
 	kfree(job_data);
 
-	if (pm_runtime_enabled(client->base.dev))
+	if (pm_runtime_enabled(client->base.dev)) {
+		pm_runtime_mark_last_busy(client->base.dev);
 		pm_runtime_put_autosuspend(client->base.dev);
+	}
 }
 
 int tegra_drm_ioctl_channel_submit(struct drm_device *drm, void *data,