watchdog: Add support for Freescale Layerscape platforms

Modify watchdog/Kconfig file to support Layerscape platforms.
Signed-off-by: NShaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: NHou Zhiqiang <B48286@freescale.com>
Acked-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

drivers/watchdog/Kconfig

@@ -446,7 +446,7 @@ config MAX63XX_WATCHDOG
 
 config IMX2_WDT
 	tristate "IMX2+ Watchdog"
-	depends on ARCH_MXC
+	depends on ARCH_MXC || ARCH_LAYERSCAPE
 	select REGMAP_MMIO
 	select WATCHDOG_CORE
 	help