ARM: imx: use __iomem pointers for MMIO

ARM is moving to stricter checks on readl/write functions,
so we need to use the correct types everywhere.

This found a bug in mach-armadillo5x0.c, where we attempt mmio
on the MXC_CCM_RCSR address that is currently defined to 0xc
and consequently causes an illegal address access.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Shawn Guo <shawn.guo@linaro.org>

arch/arm/mach-imx/mach-mx31ads.c

@@ -540,7 +540,7 @@ static void __init mxc_init_audio(void)
  */
 static struct map_desc mx31ads_io_desc[] __initdata = {
 	{
-		.virtual	= MX31_CS4_BASE_ADDR_VIRT,
+		.virtual	= (unsigned long)MX31_CS4_BASE_ADDR_VIRT,
 		.pfn		= __phys_to_pfn(MX31_CS4_BASE_ADDR),
 		.length		= CS4_CS8900_MMIO_START,
 		.type		= MT_DEVICE