style: use system path for dbus headers

Use system path for dbus headers.

Change-Id: I08088eb0932de738fc410104c28847aaf78d95bd
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/pid/zone.hpp b/pid/zone.hpp
index e04eeb7..3e2166c 100644
--- a/pid/zone.hpp
+++ b/pid/zone.hpp
@@ -5,7 +5,6 @@
 #include "pidcontroller.hpp"
 #include "sensors/manager.hpp"
 #include "sensors/sensor.hpp"
-#include "xyz/openbmc_project/Control/Mode/server.hpp"
 
 #include <fstream>
 #include <map>
@@ -15,6 +14,7 @@
 #include <set>
 #include <string>
 #include <vector>
+#include <xyz/openbmc_project/Control/Mode/server.hpp>
 
 template <typename... T>
 using ServerObject = typename sdbusplus::server::object::object<T...>;