Fix ordering of an entry in cmake.

Change-Id: I7731cbfbfd8256d2711e25156663d85ce3d68b24

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 39c3285..6bc16da 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -152,8 +152,8 @@
             "${AOM_ROOT}/aom/src/aom_integer.c")
 
 list(APPEND AOM_COMMON_APP_UTIL_SOURCES
-            "${AOM_ROOT}/av1/arg_defs.h"
             "${AOM_ROOT}/av1/arg_defs.c"
+            "${AOM_ROOT}/av1/arg_defs.h"
             "${AOM_ROOT}/common/args_helper.c"
             "${AOM_ROOT}/common/args_helper.h"
             "${AOM_ROOT}/common/args.c"