ARM: imx: dynamically allocate imx2-wdt devices

Currently there is no platform data used in the driver.  In case this
changes and for consistency NULL is passed unused to the soc specific
functions.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
diff --git a/arch/arm/plat-mxc/devices/Kconfig b/arch/arm/plat-mxc/devices/Kconfig
index 37d7e00..01b0d0c 100644
--- a/arch/arm/plat-mxc/devices/Kconfig
+++ b/arch/arm/plat-mxc/devices/Kconfig
@@ -13,6 +13,9 @@
 	bool
 	default y if ARCH_MX51
 	
+config IMX_HAVE_PLATFORM_IMX2_WDT
+	bool
+
 config IMX_HAVE_PLATFORM_IMX_I2C
 	bool