ALSA: hda - Add hint string helper functions

Added snd_hda_get_hint() and snd_hda_get_bool_hint() helper functions
to retrieve a hint value.

Internally, the hint is stored in a pair of two strings, key and val.

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 03ee9dd..27428c7 100644
--- a/sound/pci/hda/hda_local.h
+++ b/sound/pci/hda/hda_local.h
@@ -433,6 +433,23 @@
 }
 #endif
 
+#ifdef CONFIG_SND_HDA_RECONFIG
+const char *snd_hda_get_hint(struct hda_codec *codec, const char *key);
+int snd_hda_get_bool_hint(struct hda_codec *codec, const char *key);
+#else
+static inline
+const char *snd_hda_get_hint(struct hda_codec *codec, const char *key)
+{
+	return NULL;
+}
+
+static inline
+int snd_hda_get_bool_hint(struct hda_codec *codec, const char *key)
+{
+	return -ENOENT;
+}
+#endif
+
 /*
  * power-management
  */