Remove compile guards for CONFIG_EXT_REFS

This experiment has been adopted, we can simplify the code
by dropping the associated preprocessor conditionals.

Change-Id: I4705652ac8231ee25f960e8096dc97c2aeed1d20
diff --git a/examples/inspect.c b/examples/inspect.c
index 595cb02..a2226c1 100644
--- a/examples/inspect.c
+++ b/examples/inspect.c
@@ -128,14 +128,9 @@
 } map_entry;
 
 const map_entry refs_map[] = { ENUM(INTRA_FRAME),  ENUM(LAST_FRAME),
-#if CONFIG_EXT_REFS
                                ENUM(LAST2_FRAME),  ENUM(LAST3_FRAME),
                                ENUM(GOLDEN_FRAME), ENUM(BWDREF_FRAME),
-                               ENUM(ALTREF_FRAME),
-#else
-                               ENUM(GOLDEN_FRAME), ENUM(ALTREF_FRAME),
-#endif
-                               LAST_ENUM };
+                               ENUM(ALTREF_FRAME), LAST_ENUM };
 
 const map_entry block_size_map[] = {
 #if CONFIG_CHROMA_2X2 || CONFIG_CHROMA_SUB8X8