kern: implement smmu init

libraries/libmesosphere/include/mesosphere/kern_k_device_address_space.hpp

@@ -17,12 +17,15 @@
 #include <mesosphere/kern_common.hpp>
 #include <mesosphere/kern_k_auto_object.hpp>
 #include <mesosphere/kern_slab_helpers.hpp>
+#include <mesosphere/kern_select_device_page_table.hpp>
 
 namespace ams::kern {
 
     class KDeviceAddressSpace final : public KAutoObjectWithSlabHeapAndContainer<KDeviceAddressSpace, KAutoObjectWithList> {
         MESOSPHERE_AUTOOBJECT_TRAITS(KDeviceAddressSpace, KAutoObject);
         public:
+            static void Initialize();
+
             /* TODO: This is a placeholder definition. */
     };