drm/msm: Implement shutdown callback for adreno

Implement the shutdown callback for adreno gpu platform device
to safely shutdown it before a system reboot. This helps to avoid
futher transactions from gpu after the smmu is moved to bypass mode.
Signed-off-by: Akhil P Oommen <akhilpo@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/adreno/adreno_device.c

@@ -475,6 +475,11 @@ static int adreno_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static void adreno_shutdown(struct platform_device *pdev)
+{
+	pm_runtime_force_suspend(&pdev->dev);
+}
+
 static const struct of_device_id dt_match[] = {
 	{ .compatible = "qcom,adreno" },
 	{ .compatible = "qcom,adreno-3xx" },
@@ -509,6 +514,7 @@ static const struct dev_pm_ops adreno_pm_ops = {
 static struct platform_driver adreno_driver = {
 	.probe = adreno_probe,
 	.remove = adreno_remove,
+	.shutdown = adreno_shutdown,
 	.driver = {
 		.name = "adreno",
 		.of_match_table = dt_match,