Update reference.md

EEPROM location is not static

Author: plinioseniore

hardware/esp8266com/esp8266/doc/reference.md

@@ -382,7 +382,7 @@ Size can be anywhere between 4 and 4096 bytes.
 whenever you wish to save changes to flash. `EEPROM.end()` will also commit, and will
 release the RAM copy of EEPROM contents.
 
-EEPROM library uses one sector of flash located at 0x7b000 for storage.
+EEPROM library uses one sector of flash located just after the SPIFFS.
 
 Three examples included.