fix(board): add LED_BUILTIN #define

Author: SuGlider

variants/Geekble_Nano_ESP32S3/pins_arduino.h

@@ -36,6 +36,9 @@ static const uint8_t A7 = 14;
 // alternate pin functions
 
 static const uint8_t LED_BUILTIN = D13;
+#define BUILTIN_LED LED_BUILTIN  // backward compatibility
+#define LED_BUILTIN LED_BUILTIN  // allow testing #ifdef LED_BUILTIN
+
 static const uint8_t SW_BUILTIN = 0;
 
 static const uint8_t TX = D1;