ARM: at91: use __iomem pointers for MMIO

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

Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/mach-at91/at91x40.c

@@ -47,7 +47,7 @@ static void at91x40_idle(void)
 	 * Disable the processor clock.  The processor will be automatically
 	 * re-enabled by an interrupt or by a reset.
 	 */
-	__raw_writel(AT91_PS_CR_CPU, AT91_PS_CR);
+	__raw_writel(AT91_PS_CR_CPU, AT91_IO_P2V(AT91_PS_CR));
 	cpu_do_idle();
 }