This patch adds a board_reset function to allow boards to specify
their own custom reset sequence (e.g. resetting by timing out watchdog).
Tested only on MCF5271, can be expanded if needed.
Based on Mike Frysinger's suggestion on:
http://article.gmane.org/gmane.comp.boot-loaders.u-boot/70304
Signed-off-by: Richard Retanubun <RichardRetanubun at RuggedCom.com>
