remove the dependency on idct.h

Change-Id: Idcf827d8ae6429ee5b673c3398f838dbeacb4e74
diff --git a/test/dct16x16_test.cc b/test/dct16x16_test.cc
index d857280..64bf0bb 100644
--- a/test/dct16x16_test.cc
+++ b/test/dct16x16_test.cc
@@ -16,7 +16,6 @@
 
 extern "C" {
 #include "vp9/common/entropy.h"
-#include "vp9/common/idct.h"
 #include "vp9_rtcd.h"
 }
 
diff --git a/vp9/vp9_common.mk b/vp9/vp9_common.mk
index d6c9b2b..7b77231 100644
--- a/vp9/vp9_common.mk
+++ b/vp9/vp9_common.mk
@@ -38,7 +38,6 @@
 VP9_COMMON_SRCS-yes += common/extend.h
 VP9_COMMON_SRCS-yes += common/findnearmv.h
 VP9_COMMON_SRCS-yes += common/header.h
-VP9_COMMON_SRCS-yes += common/idct.h
 VP9_COMMON_SRCS-yes += common/invtrans.h
 VP9_COMMON_SRCS-yes += common/loopfilter.h
 VP9_COMMON_SRCS-yes += common/modecont.h