ALSA: PCI: Replace CONFIG_PM with CONFIG_PM_SLEEP

Otherwise we may get compile warnings due to unused functions.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/nm256/nm256.c b/sound/pci/nm256/nm256.c
index 465cff2..e80e9a1 100644
--- a/sound/pci/nm256/nm256.c
+++ b/sound/pci/nm256/nm256.c
@@ -1377,7 +1377,7 @@
 	return 0;
 }
 
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 /*
  * APM event handler, so the card is properly reinitialized after a power
  * event.
@@ -1441,7 +1441,7 @@
 #define NM256_PM_OPS	&nm256_pm
 #else
 #define NM256_PM_OPS	NULL
-#endif /* CONFIG_PM */
+#endif /* CONFIG_PM_SLEEP */
 
 static int snd_nm256_free(struct nm256 *chip)
 {