ALSA: hda - Constify some API function arguments

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_local.h b/sound/pci/hda/hda_local.h
index ff5e2ac..f36af37 100644
--- a/sound/pci/hda/hda_local.h
+++ b/sound/pci/hda/hda_local.h
@@ -347,7 +347,7 @@
                                int num_configs, const char * const *models,
                                const struct snd_pci_quirk *tbl);
 int snd_hda_add_new_ctls(struct hda_codec *codec,
-			 struct snd_kcontrol_new *knew);
+			 const struct snd_kcontrol_new *knew);
 
 /*
  * unsolicited event handler
@@ -567,7 +567,7 @@
 };
 
 struct hda_loopback_check {
-	struct hda_amp_list *amplist;
+	const struct hda_amp_list *amplist;
 	int power_on;
 };