eeprom: add `skip' options + tidy-up LOG messages

* add skip option to the eeprom -o command to jump to a specific
  address in the EEPROM before starting to read or write

* remove extra line endings in some LOG messages
eeprom: enable EEPROM I2C address from config file

When `-o addr=CONFIG' is used, the EEPROM I2C address is searched
in the config file under the [plhwtools] section with the key
specified by CONFIG.  If not found, the value passed with -a will
be used.  If -a value is provided then plhwtools will abort and
report an error.
eeprom: add addr option to help message
ChangeLog v1.2 -> v1.3