drm/tegra: dc: Turn off and reset hardware across suspend-resume

The drivers core bumps runtime PM refcount during of entering into suspend to workaround some problem where parent device may become turned off before its children. For now CRTCs are only getting disabled on suspend and in order to actually suspend the display controllers hardware, the runtime PM needed to be "forced" into suspend mode.

---
 drivers/gpu/drm/tegra/dc.c | 2 ++
 1 file changed, 2 insertions(+)

index 4a75d149e368..6c8f5222d558 100644
@@ -2572,6 +2572,8 @@ static int tegra_dc_resume(struct device *dev)
 
 static const struct dev_pm_ops tegra_dc_pm_ops = {
 	SET_RUNTIME_PM_OPS(tegra_dc_suspend, tegra_dc_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
 };
 
 struct platform_driver tegra_dc_driver = {

2.22.0