need to add E2END to pins_RAMPS_FD_V2.h (#11564)

Marlin/src/pins/pins_RAMPS_FD_V2.h

 #undef INVERTED_FAN_PINS
 
 #define I2C_EEPROM
+#define E2END 0xFFFF // 64K in a 24C512
 
 #ifndef PS_ON_PIN
   #define PS_ON_PIN        12