ASoC: add static inline funcs to fix a compiling issue

When CONFIG_PM_SLEEP is not selected, calling funcs
snd_soc_suspend and _resume will generate a compiling
issue.

Here add static inline stub functions to fix it.

Signed-off-by: Jie Yang <yang.jie@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc.h

@@ -387,8 +387,20 @@ int snd_soc_codec_set_pll(struct snd_soc_codec *codec, int pll_id, int source,
 int snd_soc_register_card(struct snd_soc_card *card);
 int snd_soc_unregister_card(struct snd_soc_card *card);
 int devm_snd_soc_register_card(struct device *dev, struct snd_soc_card *card);
+#ifdef CONFIG_PM_SLEEP
 int snd_soc_suspend(struct device *dev);
 int snd_soc_resume(struct device *dev);
+#else
+static inline int snd_soc_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static inline int snd_soc_resume(struct device *dev)
+{
+	return 0;
+}
+#endif
 int snd_soc_poweroff(struct device *dev);
 int snd_soc_register_platform(struct device *dev,
 		const struct snd_soc_platform_driver *platform_drv);