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/oxygen/oxygen.c b/sound/pci/oxygen/oxygen.c
index 37520a2b4..2becae1 100644
--- a/sound/pci/oxygen/oxygen.c
+++ b/sound/pci/oxygen/oxygen.c
@@ -872,7 +872,7 @@
 	.id_table = oxygen_ids,
 	.probe = generic_oxygen_probe,
 	.remove = __devexit_p(oxygen_pci_remove),
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 	.driver = {
 		.pm = &oxygen_pci_pm,
 	},