bnxt_en: Add Support for ETHTOOL_GMODULEINFO and ETHTOOL_GMODULEEEPRO

Add support to fetch the SFP EEPROM settings from the firmware
and display it via the ethtool -m command.  We support SFP+ and QSFP
modules.

v2: Fixed a bug in bnxt_get_module_eeprom() found by Ben Hutchings.

Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>