ASoC: cs43130: Fix unused compiler warnings for PM runtime

Add __maybe_unused prefix for addressing the following warnings:
  sound/soc/codecs/cs43130.c:2615:12: warning: ‘cs43130_runtime_resume’ defined but not used [-Wunused-function]
  sound/soc/codecs/cs43130.c:2596:12: warning: ‘cs43130_runtime_suspend’ defined but not used [-Wunused-function]

Fixes: 8f1e5bf9b4 ("ASoC: cs43130: Add support for CS43130 codec")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/cs43130.c

@@ -2597,7 +2597,7 @@ static int cs43130_i2c_remove(struct i2c_client *client)
 	return 0;
 }
 
-static int cs43130_runtime_suspend(struct device *dev)
+static int __maybe_unused cs43130_runtime_suspend(struct device *dev)
 {
 	struct cs43130_private *cs43130 = dev_get_drvdata(dev);
 
@@ -2616,7 +2616,7 @@ static int cs43130_runtime_suspend(struct device *dev)
 	return 0;
 }
 
-static int cs43130_runtime_resume(struct device *dev)
+static int __maybe_unused cs43130_runtime_resume(struct device *dev)
 {
 	struct cs43130_private *cs43130 = dev_get_drvdata(dev);
 	int ret;