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/ge_bx50v3_defconfig b/configs/ge_bx50v3_defconfig
index 7351659..75fdbf7 100644
--- a/configs/ge_bx50v3_defconfig
+++ b/configs/ge_bx50v3_defconfig
@@ -61,5 +61,6 @@
 CONFIG_MXC_SPI=y
 CONFIG_DM_VIDEO=y
 CONFIG_VIDEO_IPUV3=y
+CONFIG_WATCHDOG_TIMEOUT_MSECS=6000
 CONFIG_IMX_WATCHDOG=y
 # CONFIG_EFI_LOADER is not set