[WATCHDOG] watchdog-driver-for-at32ap700x-devices-fix-2

standard ifdef-reduction trick.

Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>