Add Polaris Chord Support (#361)

## Link to GitHub Issue, if one exists
n/a

## Description of change
Adds support for Polaris Chord

## Testing
Tested with XIF:J:A:A:2024122300. IO/ICCA works, game successfully
connects to server and is playable.

src/spice2x/games/pc/io.h

@@ -0,0 +1,52 @@
+#pragma once
+
+#include <vector>
+#include "cfg/api.h"
+
+namespace games::pc {
+    namespace Buttons {
+        enum {
+            Service,
+            Test,
+            CoinMech,
+            Button1,
+            Button2,
+            Button3,
+            Button4,
+            Button5,
+            Button6,
+            Button7,
+            Button8,
+            Button9,
+            Button10,
+            Button11,
+            Button12,
+            FaderL_Left,
+            FaderL_Right,
+            FaderR_Left,
+            FaderR_Right,
+            Headphone
+        };
+    }
+
+    namespace Analogs {
+        enum {
+            FaderL,
+            FaderR,
+        };
+    }
+
+    namespace Lights {
+        typedef enum {
+            IC_READER_R,
+            IC_READER_G,
+            IC_READER_B,
+        } pc_lights_t;
+    }
+
+    // getters
+    std::vector<Button> &get_buttons();
+    std::string get_buttons_help();
+    std::vector<Analog> &get_analogs();
+    std::vector<Light> &get_lights();
+}