Add missing frame ref enum to the inspector

Change-Id: I35a5334972b73bdf31d6476d376af982c964a54b
diff --git a/examples/inspect.c b/examples/inspect.c
index ec33bca..5c553d2 100644
--- a/examples/inspect.c
+++ b/examples/inspect.c
@@ -143,10 +143,11 @@
   int value;
 } map_entry;
 
-const map_entry refs_map[] = { ENUM(INTRA_FRAME),  ENUM(LAST_FRAME),
-                               ENUM(LAST2_FRAME),  ENUM(LAST3_FRAME),
-                               ENUM(GOLDEN_FRAME), ENUM(BWDREF_FRAME),
-                               ENUM(ALTREF_FRAME), LAST_ENUM };
+const map_entry refs_map[] = {
+  ENUM(INTRA_FRAME),   ENUM(LAST_FRAME),   ENUM(LAST2_FRAME),
+  ENUM(LAST3_FRAME),   ENUM(GOLDEN_FRAME), ENUM(BWDREF_FRAME),
+  ENUM(ALTREF2_FRAME), ENUM(ALTREF_FRAME), LAST_ENUM
+};
 
 const map_entry block_size_map[] = {
   ENUM(BLOCK_2X2),    ENUM(BLOCK_2X4),    ENUM(BLOCK_4X2),