watchdog: Driver for the watchdog timer on Freescale IMX2 (and later) processors.

This is the driver for the hardware watchdog on the Freescale IMX2 and later processors.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Vladimir Zapolskiy <vzapolskiy@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>