update .clang-format

Added the header inclusion order to the .clang-format file generated
these changes.

Change-Id: I4f51a20f469de431ee6a5ba78e3f4da39c980fab
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/src/event_serialize.cpp b/src/event_serialize.cpp
index ddfc4b6..ca43c41 100644
--- a/src/event_serialize.cpp
+++ b/src/event_serialize.cpp
@@ -1,11 +1,12 @@
-#include <cereal/types/string.hpp>
-#include <cereal/types/vector.hpp>
-#include <cereal/archives/binary.hpp>
-#include <fstream>
+#include "config.h"
 
 #include "event_serialize.hpp"
+
+#include <cereal/archives/binary.hpp>
+#include <cereal/types/string.hpp>
+#include <cereal/types/vector.hpp>
+#include <fstream>
 #include <phosphor-logging/log.hpp>
-#include "config.h"
 
 // Register class version
 // From cereal documentation;