Rollback "DSP on Thread" to only affect LLE.

Keep the threading code in AX HLE in case we want/need to enable it again at
some point. Not too confident about refactoring it right now.

Source/Core/Core/Src/HW/DSPHLE/UCodes/UCode_AX.cpp

@@ -14,14 +14,17 @@ CUCode_AX::CUCode_AX(DSPHLE* dsp_hle, u32 crc)
 	: IUCode(dsp_hle, crc)
 	, m_work_available(false)
 	, m_cmdlist_size(0)
-	, m_run_on_thread(SConfig::GetInstance().m_LocalCoreStartupParameter.bDSPThread)
+	, m_run_on_thread(false)
 {
 	WARN_LOG(DSPHLE, "Instantiating CUCode_AX: crc=%08x", crc);
 	m_rMailHandler.PushMail(DSP_INIT);
 	DSP::GenerateDSPInterruptFromDSPEmu(DSP::INT_DSP);
 
 	LoadResamplingCoefficients();
 
+	// DSP HLE on thread is always disabled because it causes audio
+	// issues/glitching (different timing characteristics). m_run_on_thread is
+	// always false.
 	if (m_run_on_thread)
 		m_axthread = std::thread(SpawnAXThread, this);
 }

Source/Core/DolphinWX/Src/ConfigMain.cpp

@@ -502,7 +502,7 @@ void CConfigMain::InitializeGUITooltips()
 	InterfaceLang->SetToolTip(_("Change the language of the user interface.\nRequires restart."));
 
 	// Audio tooltips
-	DSPThread->SetToolTip(_("Run DSP HLE and LLE on a dedicated thread (not recommended: might cause audio glitches with HLE and freezes with LLE)."));
+	DSPThread->SetToolTip(_("Run DSP LLE on a dedicated thread (not recommended: might cause freezes)."));
 	BackendSelection->SetToolTip(_("Changing this will have no effect while the emulator is running!"));
 
 	// Gamecube - Devices
@@ -643,7 +643,7 @@ void CConfigMain::CreateGUIControls()
 	// Audio page
 	DSPEngine = new wxRadioBox(AudioPage, ID_DSPENGINE, _("DSP Emulator Engine"),
 				wxDefaultPosition, wxDefaultSize, arrayStringFor_DSPEngine, 0, wxRA_SPECIFY_ROWS);
-	DSPThread = new wxCheckBox(AudioPage, ID_DSPTHREAD, _("DSP on Dedicated Thread"));
+	DSPThread = new wxCheckBox(AudioPage, ID_DSPTHREAD, _("DSPLLE on Separate Thread"));
 	DumpAudio = new wxCheckBox(AudioPage, ID_DUMP_AUDIO, _("Dump Audio"),
 				wxDefaultPosition, wxDefaultSize, 0, wxDefaultValidator);
 	DPL2Decoder = new wxCheckBox(AudioPage, ID_DPL2DECODER, _("Dolby Pro Logic II decoder"));