Update gpio_irq_api.c

Author: ThunderSoft123

targets/TARGET_TT/TARGET_TT_M3HQ/gpio_irq_api.c

@@ -462,13 +462,8 @@ static uint32_t CheckPinNameIRQSRC(PinName pin)
             return CG_INT_SRC_18;
         case PT1:
             return CG_INT_SRC_19;
-        //Expand:
-        //case PT2:
-        //  return CG_INT_SRC_20;
-        //case PT3:
-        //  return CG_INT_SRC_21;
         default:
             break;
     }
     return -1;
-}
+}