scope hei_includes.hpp for internal use

This file should not be included in any headers consumed by the user
application.

Signed-off-by: Zane Shelley <zshelle@us.ibm.com>
Change-Id: Ifc3ff2faa03b96c8a7ace2feb7132d74df24f5cc
diff --git a/test/simulator/sim_hardware_access.cpp b/test/simulator/sim_hardware_access.cpp
index d0625cc..370b92f 100644
--- a/test/simulator/sim_hardware_access.cpp
+++ b/test/simulator/sim_hardware_access.cpp
@@ -7,8 +7,8 @@
 
 #include <endian.h>
 
-#include <hei_includes.hpp>
 #include <hei_user_interface.hpp>
+#include <util/hei_includes.hpp>
 
 namespace libhei
 {