Improved cache maintenance

Use invalidate by address to avoid invalidating the data segment
loosing data.

Change-Id: Ied36d881d19e56ea760b8775657b0e924e129b31
diff --git a/applications/message_process/include/message_process.hpp b/applications/message_process/include/message_process.hpp
index b3c1bdd..602c2a4 100644
--- a/applications/message_process/include/message_process.hpp
+++ b/applications/message_process/include/message_process.hpp
@@ -78,6 +78,11 @@
     }
 
 private:
+    void cleanHeader() const;
+    void cleanHeaderData() const;
+    void invalidateHeader() const;
+    void invalidateHeaderData() const;
+
     ethosu_core_queue &queue;
 };