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.h b/sound/pci/oxygen/oxygen.h
index 7112a89..09a24b2 100644
--- a/sound/pci/oxygen/oxygen.h
+++ b/sound/pci/oxygen/oxygen.h
@@ -161,7 +161,7 @@
 				     )
 		    );
 void oxygen_pci_remove(struct pci_dev *pci);
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 extern const struct dev_pm_ops oxygen_pci_pm;
 #endif
 void oxygen_pci_shutdown(struct pci_dev *pci);