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/ctxfi/xfi.c b/sound/pci/ctxfi/xfi.c
index e002183..07c07d7 100644
--- a/sound/pci/ctxfi/xfi.c
+++ b/sound/pci/ctxfi/xfi.c
@@ -125,7 +125,7 @@
 	pci_set_drvdata(pci, NULL);
 }
 
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 static int ct_card_suspend(struct device *dev)
 {
 	struct snd_card *card = dev_get_drvdata(dev);