arm: call iommu_init before of_platform_populate

We need to ensure that the IOMMUs in the system have a chance to perform
some basic initialisation before we start adding masters to them.

This patch adds a call to of_iommu_init before of_platform_populate.
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm/kernel/setup.c

@@ -18,6 +18,7 @@
 #include <linux/bootmem.h>
 #include <linux/seq_file.h>
 #include <linux/screen_info.h>
+#include <linux/of_iommu.h>
 #include <linux/of_platform.h>
 #include <linux/init.h>
 #include <linux/kexec.h>
@@ -806,6 +807,7 @@ static int __init customize_machine(void)
 	 * machine from the device tree, if no callback is provided,
 	 * otherwise we would always need an init_machine callback.
 	 */
+	of_iommu_init();
 	if (machine_desc->init_machine)
 		machine_desc->init_machine();
 #ifdef CONFIG_OF