yuzu: Save sound output mode and set it to Stereo by default

src/core/settings.h

@@ -387,6 +387,7 @@ struct Values {
 
     s32 current_user;
     s32 language_index;
+    s32 sound_index;
 
     // Controls
     std::array<PlayerInput, 10> players;

src/yuzu/configuration/config.cpp

@@ -698,6 +698,8 @@ void Config::ReadSystemValues() {
         Settings::values.custom_rtc = std::nullopt;
     }
 
+    Settings::values.sound_index = ReadSetting(QStringLiteral("sound_index"), 1).toInt();
+
     qt_config->endGroup();
 }
 
@@ -1125,6 +1127,8 @@ void Config::SaveSystemValues() {
                      Settings::values.custom_rtc.value_or(std::chrono::seconds{}).count()),
                  0);
 
+    WriteSetting(QStringLiteral("sound_index"), Settings::values.sound_index, 1);
+
     qt_config->endGroup();
 }
 

src/yuzu/configuration/configure_system.cpp

@@ -56,6 +56,7 @@ void ConfigureSystem::SetConfiguration() {
     enabled = !Core::System::GetInstance().IsPoweredOn();
 
     ui->combo_language->setCurrentIndex(Settings::values.language_index);
+    ui->combo_sound->setCurrentIndex(Settings::values.sound_index);
 
     ui->rng_seed_checkbox->setChecked(Settings::values.rng_seed.has_value());
     ui->rng_seed_edit->setEnabled(Settings::values.rng_seed.has_value());
@@ -81,6 +82,7 @@ void ConfigureSystem::ApplyConfiguration() {
     }
 
     Settings::values.language_index = ui->combo_language->currentIndex();
+    Settings::values.sound_index = ui->combo_sound->currentIndex();
 
     if (ui->rng_seed_checkbox->isChecked()) {
         Settings::values.rng_seed = ui->rng_seed_edit->text().toULongLong(nullptr, 16);