service/prepo: Move class into the cpp file

This doesn't need to be exposed within the header and be kept in the
translation unit, eliminating the need to include anything within the
header.

src/core/hle/service/prepo/prepo.h

@@ -4,22 +4,12 @@
 
 #pragma once
 
-#include <memory>
-#include <string>
-#include "core/hle/kernel/event.h"
-#include "core/hle/service/service.h"
+namespace Service::SM {
+class ServiceManager;
+}
 
 namespace Service::PlayReport {
 
-class PlayReport final : public ServiceFramework<PlayReport> {
-public:
-    explicit PlayReport(const char* name);
-    ~PlayReport() = default;
-
-private:
-    void SaveReportWithUser(Kernel::HLERequestContext& ctx);
-};
-
 void InstallInterfaces(SM::ServiceManager& service_manager);
 
 } // namespace Service::PlayReport