Add HardwareSerial.h to deprecation list

Author: facchinm

Diff for: api/deprecated/HardwareSerial.h

@@ -0,0 +1,25 @@
+/*
+  Copyright (c) 2016 Arduino LLC.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+  See the GNU Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+// including HardwareSerial.h is deprecated, for all future projects use Arduino.h instead
+
+// This include is added for compatibility, it will be remove on the next
+// major release of the API
+#include "../HardwareSerial.h"
+
+