service: add os types and multi wait API

src/core/hle/service/os/mutex.h

@@ -0,0 +1,31 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "common/common_types.h"
+
+namespace Core {
+class System;
+}
+
+namespace Kernel {
+class KEvent;
+}
+
+namespace Service {
+
+class Mutex {
+public:
+    explicit Mutex(Core::System& system);
+    ~Mutex();
+
+    void lock();
+    void unlock();
+
+private:
+    Core::System& m_system;
+    Kernel::KEvent* m_event{};
+};
+
+} // namespace Service