hle_ipc: Refactor SleepClientThread to avoid ReadableEvent

src/core/hle/service/am/am.cpp

@@ -302,6 +302,7 @@ void ISelfController::GetLibraryAppletLaunchableEvent(Kernel::HLERequestContext&
     IPC::ResponseBuilder rb{ctx, 2, 1};
     rb.Push(RESULT_SUCCESS);
     rb.PushCopyObjects(launchable_event.readable);
+}
 
 void ISelfController::SetScreenShotImageOrientation(Kernel::HLERequestContext& ctx) {
     LOG_WARNING(Service_AM, "(STUBBED) called");

src/core/hle/service/am/applets/applets.h

@@ -8,14 +8,10 @@
 #include <queue>
 #include "common/swap.h"
 #include "core/hle/kernel/kernel.h"
+#include "core/hle/kernel/writable_event.h"
 
 union ResultCode;
 
-namespace Kernel {
-class ReadableEvent;
-class WritableEvent;
-} // namespace Kernel
-
 namespace Service::AM {
 
 class IStorage;