iommu: Include linux/types.h

The linux/iommu.h header uses types defined in linux/types.h but doesn't
include it.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

include/linux/iommu.h

@@ -20,6 +20,7 @@
 #define __LINUX_IOMMU_H
 
 #include <linux/errno.h>
+#include <linux/types.h>
 
 #define IOMMU_READ	(1)
 #define IOMMU_WRITE	(2)