gitadora: (arena model) headphones i/o (#485)

## Link to GitHub Issue, if one exists
#477 

## Description of change
Plumb through headphone jack detection. Touch screen menu for headphone
volume lights up.

## Testing
Tested guitar.

src/spice2x/games/gitadora/bi2x_hook.cpp

@@ -295,13 +295,13 @@ namespace games::gitadora {
 
         memset(o_DevStatus, 0x00, sizeof(AIO_IOB2_BI2X_AC1__DEVSTATUS));
 
-        
         auto &buttons = get_buttons();
         // struct may be misaligned
         o_DevStatus->Input.CN8_10 = GameAPI::Buttons::getState(RI_MGR, buttons[Buttons::Test]) ? 0 : 0xFF;
         o_DevStatus->Input.CN9_8 = GameAPI::Buttons::getState(RI_MGR, buttons[Buttons::Service]) ? 0 : 0xFF;
         o_DevStatus->Input.CN9_9 = GameAPI::Buttons::getState(RI_MGR, buttons[Buttons::Coin]) ? 0 : 0xFF;
-        
+        o_DevStatus->Input.CN12_14 = GameAPI::Buttons::getState(RI_MGR, buttons[Buttons::Headphone]) ? 0xFF : 0;
+
         // coin
         o_DevStatus->Input.Coin1Count = eamuse_coin_get_stock();
     }

src/spice2x/games/gitadora/io.cpp

@@ -10,6 +10,7 @@ std::vector<Button> &games::gitadora::get_buttons() {
                 "Service",
                 "Test",
                 "Coin",
+                "Headphone",
                 "Guitar P1 Start",
                 "Guitar P1 Up",
                 "Guitar P1 Down",

src/spice2x/games/gitadora/io.h

@@ -11,6 +11,7 @@ namespace games::gitadora {
             Service,
             Test,
             Coin,
+            Headphone,
             GuitarP1Start,
             GuitarP1Up,
             GuitarP1Down,