Add extra `GBAAddon` entries for the Boktai carts

- Each game in the trilogy has a different effect on Lunar Knights (the only commercial DS game to support the solar sensor)

src/NDS.h

@@ -211,6 +211,12 @@ enum
 {
     GBAAddon_RAMExpansion = 1,
     GBAAddon_RumblePak = 2,
+    // Each game in the GBA Boktai trilogy uses the same solar sensor,
+    // but Lunar Knights (the only NDS game to use the solar sensor)
+    // applies slightly different effects depending on the game.
+    GBAAddon_SolarSensorBoktai1 = 3,
+    GBAAddon_SolarSensorBoktai2 = 4,
+    GBAAddon_SolarSensorBoktai3 = 5,
 };
 
 class SPU;

src/frontend/qt_sdl/EmuInstance.cpp

@@ -2088,6 +2088,12 @@ QString EmuInstance::gbaAddonName(int addon)
         return "Rumble Pak";
     case GBAAddon_RAMExpansion:
         return "Memory expansion";
+    case GBAAddon_SolarSensorBoktai1:
+        return "Solar Sensor (Boktai 1)";
+    case GBAAddon_SolarSensorBoktai2:
+        return "Solar Sensor (Boktai 2)";
+    case GBAAddon_SolarSensorBoktai3:
+        return "Solar Sensor (Boktai 3)";
     }
 
     return "???";

src/frontend/qt_sdl/Window.cpp

@@ -320,7 +320,7 @@ MainWindow::MainWindow(int id, EmuInstance* inst, QWidget* parent) :
                 QMenu * submenu = menu->addMenu("Insert add-on cart");
                 QAction *act;
 
-                int addons[] = {GBAAddon_RAMExpansion, GBAAddon_RumblePak, -1};
+                int addons[] = {GBAAddon_RAMExpansion, GBAAddon_RumblePak, GBAAddon_SolarSensorBoktai1, GBAAddon_SolarSensorBoktai2, GBAAddon_SolarSensorBoktai3, -1};
                 for (int i = 0; addons[i] != -1; i++)
                 {
                     int addon = addons[i];