add copyright info (#251)

Add copyright info according to the file history.

examples/simdize/main.cpp

@@ -1,3 +1,23 @@
+/*  This file is part of the Vc project
+    Copyright (C) 2009-2020 Matthias Kretz <kretz@kde.org>
+    Permission to use, copy, modify, and distribute this software
+    and its documentation for any purpose and without fee is hereby
+    granted, provided that the above copyright notice appear in all
+    copies and that both that the copyright notice and this
+    permission notice and warranty disclaimer appear in supporting
+    documentation, and that the name of the author not be used in
+    advertising or publicity pertaining to distribution of the
+    software without specific, written prior permission.
+    The author disclaim all warranties with regard to this
+    software, including all implied warranties of merchantability
+    and fitness.  In no event shall the author be liable for any
+    special, indirect or consequential damages or any damages
+    whatsoever resulting from loss of use, data or profits, whether
+    in an action of contract, negligence or other tortious action,
+    arising out of or in connection with the use or performance of
+    this software.
+*/
+
 #include <Vc/simdize>
 #include <Vc/IO>