Add simple EEPROM implementation for RPi

This implementation provides EEPROM like
storage for information. Its size is 1KB.
It provides the same functions as on AVR
and as used by MySensors.

Signed-off-by: Tomas Hozza <thozza@gmail.com>
Use PiEEPROM for EEPROM operations

Signed-off-by: Tomas Hozza <thozza@gmail.com>