ARM: imx: dynamically allocate mxc_w1 devices

Currently there is no platform data used in the driver.  In case this
changes 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/mach-imx/mach-mx27ads.c b/arch/arm/mach-imx/mach-mx27ads.c
index a1e4bc5..219899a 100644
--- a/arch/arm/mach-imx/mach-mx27ads.c
+++ b/arch/arm/mach-imx/mach-mx27ads.c
@@ -284,7 +284,6 @@
 
 static struct platform_device *platform_devices[] __initdata = {
 	&mx27ads_nor_mtd_device,
-	&mxc_w1_master_device,
 };
 
 static const struct imxuart_platform_data uart_pdata __initconst = {
@@ -314,6 +313,7 @@
 
 	imx27_add_fec(NULL);
 	platform_add_devices(platform_devices, ARRAY_SIZE(platform_devices));
+	imx27_add_mxc_w1(NULL);
 }
 
 static void __init mx27ads_timer_init(void)