ASoC: tegra20: i2s: Add system level suspend-resume callbacks

Add system level suspend-resume callbacks in order to ensure that I2S
is gated before system is suspended. This puts Tegra20 I2S driver on
par with the Tegra30 I2S driver.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210314154459.15375-9-digetx@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/tegra/tegra20_i2s.c

@@ -460,6 +460,8 @@ static const struct of_device_id tegra20_i2s_of_match[] = {
 static const struct dev_pm_ops tegra20_i2s_pm_ops = {
 	SET_RUNTIME_PM_OPS(tegra20_i2s_runtime_suspend,
 			   tegra20_i2s_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
 };
 
 static struct platform_driver tegra20_i2s_driver = {