watchdog: bd70528: Trivial function documentation fix

The function documentation for the exported  ROHM BD70528 WDG control
functions used old argument names. Fix the names.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20191010060733.GA9979@localhost.localdomain


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>