[Kernel] Use tables for export groups.

src/xenia/kernel/xam/xam_nui.cc

@@ -66,9 +66,8 @@ dword_result_t XamShowNuiTroubleshooterUI_entry(unknown_t unk1, unknown_t unk2,
 }
 DECLARE_XAM_EXPORT1(XamShowNuiTroubleshooterUI, kNone, kStub);
 
-void RegisterNUIExports(xe::cpu::ExportResolver* export_resolver,
-                        KernelState* kernel_state) {}
-
 }  // namespace xam
 }  // namespace kernel
 }  // namespace xe
+
+DECLARE_XAM_EMPTY_REGISTER_EXPORTS(NUI);