watchdog: sama5d4: fix WDD value to be always set to max

commit 8632944841d41a36d77dd1fa88d4201b5291100f upstream.

WDD value must be always set to max (0xFFF) otherwise the hardware
block will reset the board on the first ping of the watchdog.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>