Add LED_BUILTIN definition esp8266#1556

Author: narongrat

variants/espinotee/pins_arduino.h

@@ -43,6 +43,7 @@ static const uint8_t MISO  = 12;
 static const uint8_t SCK   = 14;
 
 static const uint8_t BUILTIN_LED = 16;
+static const uint8_t LED_BUILTIN = 16;
 
 static const uint8_t A0 = 17;