Reduce the scope of the header file used in vp9_context_tree.h

Change-Id: I264ee35044a5973c7725daba7af870968353a3c1
diff --git a/vp9/encoder/vp9_context_tree.h b/vp9/encoder/vp9_context_tree.h
index 97f0741..991c6e3 100644
--- a/vp9/encoder/vp9_context_tree.h
+++ b/vp9/encoder/vp9_context_tree.h
@@ -11,7 +11,7 @@
 #ifndef VP9_ENCODER_VP9_CONTEXT_TREE_H_
 #define VP9_ENCODER_VP9_CONTEXT_TREE_H_
 
-#include "vp9/common/vp9_onyxc_int.h"
+#include "vp9/common/vp9_entropymode.h"
 
 struct VP9_COMP;