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/display5_factory_defconfig b/configs/display5_factory_defconfig
index 5b79057..d403ad9 100644
--- a/configs/display5_factory_defconfig
+++ b/configs/display5_factory_defconfig
@@ -87,5 +87,6 @@
 CONFIG_USB_GADGET_PRODUCT_NUM=0x4000
 CONFIG_CI_UDC=y
 CONFIG_USB_GADGET_DOWNLOAD=y
+CONFIG_WATCHDOG_TIMEOUT_MSECS=15000
 CONFIG_IMX_WATCHDOG=y
 CONFIG_OF_LIBFDT=y