watchdog: move WATCHDOG_TIMEOUT_MSECS to Kconfig

move WATCHDOG_TIMEOUT_MSECS to Kconfig and fix
all board defconfigs.

Signed-off-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Stefan Roese <sr@denx.de>
Acked-by: Lukasz Majewski <lukma@denx.de>
Acked-by: Martyn Welch <martyn.welch@collabora.com>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/configs/mx53ppd_defconfig b/configs/mx53ppd_defconfig
index cad798a..7f293c8 100644
--- a/configs/mx53ppd_defconfig
+++ b/configs/mx53ppd_defconfig
@@ -50,4 +50,5 @@
 CONFIG_VIDEO_IPUV3=y
 CONFIG_VIDEO=y
 # CONFIG_VIDEO_SW_CURSOR is not set
+CONFIG_WATCHDOG_TIMEOUT_MSECS=8000
 CONFIG_IMX_WATCHDOG=y