MLKU-24-9 sound: soc: fix unused warning

When CONFIG_PM is not defined, the runtime suspend and resume
are unused so we should use __maybe_unused attribute.

Signed-off-by: Cosmin-Gabriel Samoila <cosmin.samoila@nxp.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>

sound/soc/fsl/fsl_micfil.c

@@ -2401,7 +2401,7 @@ static int __maybe_unused fsl_micfil_runtime_resume(struct device *dev)
 #endif /* CONFIG_PM*/
 
 #ifdef CONFIG_PM_SLEEP
-static int fsl_micfil_suspend(struct device *dev)
+static int __maybe_unused fsl_micfil_suspend(struct device *dev)
 {
 	struct fsl_micfil *micfil = dev_get_drvdata(dev);
 	int ret;
@@ -2421,7 +2421,7 @@ static int fsl_micfil_suspend(struct device *dev)
 	return 0;
 }
 
-static int fsl_micfil_resume(struct device *dev)
+static int __maybe_unused fsl_micfil_resume(struct device *dev)
 {
 	struct fsl_micfil *micfil = dev_get_drvdata(dev);
 	int ret;