The OMAP WDT IP block requires to be stopped before any write to its
registers is performed.
This problem has been thoroughly described in Linux kernel:
"watchdog: omap: assert the counter being stopped before reprogramming:
SHA1: 530c11d432727c697629ad5f9d00ee8e2864d453
Signed-off-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>