parts: Bug fix for i2c_eeprom part

    Fixes:

    > Part address and mask weren't set in i2c_eeprom_init. The
      virtual part responded to all addresses.
    > Mask required inverting to function as per the description in
      i2c_eeprom.h
Merge pull request #78 from dougszumski/i2c_eeprom_bugfix

parts: Bug fix for i2c_eeprom part