drm/bridge: ti-sn65dsi86: ensure bridge suspend happens during PM sleep

ti-sn65dsi86 bridge is enumerated as a runtime device. When
suspend is triggered, PM core adds a refcount on all the
devices and calls device suspend, since usage count is
already incremented, runtime suspend will not be called
and it kept the bridge regulators and gpios ON which resulted
in platform not entering into XO shutdown.

Add changes to force suspend on the runtime device during pm sleep.

Signed-off-by: Harigovindan P <harigovi@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200609120455.20458-1-harigovi@codeaurora.org

drivers/gpu/drm/bridge/ti-sn65dsi86.c

@@ -212,6 +212,8 @@ static int __maybe_unused ti_sn_bridge_suspend(struct device *dev)
 
 static const struct dev_pm_ops ti_sn_bridge_pm_ops = {
 	SET_RUNTIME_PM_OPS(ti_sn_bridge_suspend, ti_sn_bridge_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
 };
 
 static int status_show(struct seq_file *s, void *data)