arch/tile: catch up on various minor cleanups.

None of these changes fix any actual bugs, but are just various cleanups
that fell out along the way.  In particular, some unused #defines and
includes are removed, PREFETCH_STRIDE is added (the default is right for
our shipping chips, but wrong for our next generation), our tile-specific
prefetching code is removed so the (identical) generic prefetching code
can be used instead, a comment is fixed to be proper GPL and not just a
"paste GPL here" token, a "//" comment is converted to "/* */", etc.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

drivers/char/hvc_tile.c

@@ -1,15 +1,15 @@
 /*
- * %LINUX_LICENSE%
- *
- *
- *
- *
- *
- *
- *
- *
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
  *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
  *
+ *   This program 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, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
  *
  * Tilera TILE Processor hypervisor console
  */