core: settings: Untangle multicore from asynchronous GPU.

- Now that GPU is always threaded, we can support multicore with synchronous GPU.

src/core/core.cpp

@@ -159,7 +159,7 @@ struct System::Impl {
         device_memory = std::make_unique<Core::DeviceMemory>();
 
         is_multicore = Settings::values.use_multi_core.GetValue();
-        is_async_gpu = is_multicore || Settings::values.use_asynchronous_gpu_emulation.GetValue();
+        is_async_gpu = Settings::values.use_asynchronous_gpu_emulation.GetValue();
 
         kernel.SetMulticore(is_multicore);
         cpu_manager.SetMulticore(is_multicore);

src/core/settings.cpp

@@ -148,9 +148,4 @@ void RestoreGlobalState(bool is_powered_on) {
     values.motion_enabled.SetGlobal(true);
 }
 
-void Sanitize() {
-    values.use_asynchronous_gpu_emulation.SetValue(
-        values.use_asynchronous_gpu_emulation.GetValue() || values.use_multi_core.GetValue());
-}
-
 } // namespace Settings

src/core/settings.h

@@ -257,7 +257,4 @@ void LogSettings();
 // Restore the global state of all applicable settings in the Values struct
 void RestoreGlobalState(bool is_powered_on);
 
-// Fixes settings that are known to cause issues with the emulator
-void Sanitize();
-
 } // namespace Settings