ASoC: tegra20: spdif: Support system suspend

Support system suspend by enforcing runtime PM suspend/resume.
Now there is no doubt that h/w is indeed stopped during suspend
and that h/w state will be properly restored after resume.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20211204143725.31646-12-digetx@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/tegra/tegra20_spdif.c

@@ -345,6 +345,8 @@ static int tegra20_spdif_platform_probe(struct platform_device *pdev)
 static const struct dev_pm_ops tegra20_spdif_pm_ops = {
 	SET_RUNTIME_PM_OPS(tegra20_spdif_runtime_suspend,
 			   tegra20_spdif_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
 };
 
 static const struct of_device_id tegra20_spdif_of_match[] = {