ethtool: Add command to dump and parse module EEPROM

These three patches add support for the new ETHTOOL_GMODULEINFO and ETHTOOL_GMODULEEEPROM commands in net-next.

The first patch splits duplicated code used to print hex data into a function The second patch updates the the ethtool-copy.h from the net-next.
The third implements the new commands. Support for parsing SFP 8079 compatible EEPROMs has also be incorporated.

Stu