fix header description

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5594 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/endian.h

 /*
  * Asterisk -- A telephony toolkit for Linux.
  *
- * Asterisk internal frame definitions.
+ * Asterisk architecture endianess compatibility definitions
  * 
  * Copyright (C) 1999 - 2005, Digium, Inc.
  *