iRiver scramble and descramble code from Dave Cooper


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@5649 a1c6a512-1295-4272-9138-f99709370657
diff --git a/docs/CREDITS b/docs/CREDITS
index ed66027..1eaaae0 100644
--- a/docs/CREDITS
+++ b/docs/CREDITS
@@ -95,3 +95,4 @@
 Jiri Jurecek
 Jacob Erlbeck
 Jean-Philippe Bernardy
+Dave Hooper