ucm: add ValueDefaults section to the master file

- the get_value() function is recoded (tries to find the value in
  parent's list)

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

src/ucm/ucm_local.h

@@ -173,6 +173,9 @@ struct snd_use_case_mgr {
 	/* default settings - sequence */
 	struct list_head default_list;
 
+	/* default settings - value list */
+	struct list_head value_list;
+
 	/* current status */
 	struct use_case_verb *active_verb;
 	struct list_head active_devices;