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/test/interfaceaddtest.cpp b/src/test/interfaceaddtest.cpp
index d80f437..aabacf0 100644
--- a/src/test/interfaceaddtest.cpp
+++ b/src/test/interfaceaddtest.cpp
@@ -1,8 +1,10 @@
+#include "event.hpp"
+#include "pathwatchimpl.hpp"
+
 #include <array>
 #include <string>
+
 #include <gtest/gtest.h>
-#include "pathwatchimpl.hpp"
-#include "event.hpp"
 
 using namespace std::string_literals;
 using namespace phosphor::dbus::monitoring;