ponp: make Force Sub Redraw an option (#770)

## Link to GitHub Issue or related Pull Request, if one exists
n/a

## Description of change
Similar to how it is on SDVX, turning this on can cause graphical
glitches depending on the GPU, so it needs to be an option that users
can toggle.

## Testing

src/spice2x/launcher/launcher.cpp

@@ -643,6 +643,9 @@ int main_implementation(int argc, char *argv[]) {
     if (options[launcher::Options::PopnNativeTouch].value_bool()) {
         games::popn::NATIVE_TOUCH = true;
     }
+    if (options[launcher::Options::PopnSubRedraw].value_bool()) {
+        SUBSCREEN_FORCE_REDRAW = true;
+    }
     if (options[launcher::Options::LoadMetalGearArcadeModule].value_bool()) {
         attach_mga = true;
     }

src/spice2x/launcher/options.cpp

@@ -1138,6 +1138,17 @@ static const std::vector<OptionDefinition> OPTION_DEFINITIONS = {
         .game_name = "Pop'n Music",
         .category = "Advanced Game Options",
     },
+    {
+        // PopnSubRedraw
+        .title = "Pop'n Music PikaPika Subscreen Force Redraw",
+        .name = "popnsubredraw",
+        .desc = "Check if submonitor in fullscreen mode appears stuck; "
+            "this option forces subscreen to redraw every frame.",
+        .type = OptionType::Bool,
+        .game_name = "Pop'n Music",
+        .category = "Advanced Game Options",
+        .quick_setting_category = "Game",
+    },
     {
         .title = "Force Load HELLO! Pop'n Music Module",
         .name = "hpm",

src/spice2x/launcher/options.h

@@ -108,6 +108,7 @@ namespace launcher {
             PopnNoSub,
             PopnSubMonitorOverride,
             PopnNativeTouch,
+            PopnSubRedraw,
             LoadHelloPopnMusicModule,
             LoadGitaDoraModule,
             GitaDoraTwoChannelAudio,