friend: Deduplicate interfaces

src/core/hle/service/friend/interface.cpp

@@ -0,0 +1,18 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/hle/service/friend/interface.h"
+
+namespace Service::Friend {
+
+Friend::Friend(std::shared_ptr<Module> module, const char* name)
+    : Interface(std::move(module), name) {
+    static const FunctionInfo functions[] = {
+        {0, &Friend::CreateFriendService, "CreateFriendService"},
+        {1, nullptr, "CreateNotificationService"},
+    };
+    RegisterHandlers(functions);
+}
+
+} // namespace Service::Friend