ixgbe: add E610 functions getting PBA and FW ver info

Introduce 2 E610 specific callbacks implementations:
-ixgbe_start_hw_e610() which expands the regular .start_hw callback with
getting FW version information
-ixgbe_read_pba_string_e610() which gets Product Board Assembly string

Extend EEPROM ops with new .read_pba_string in order to distinguish
generic one and the E610 one.

Reviewed-by: Mateusz Polchlopek <mateusz.polchlopek@intel.com>
Tested-by: Bharath R <bharath.r@intel.com>
Co-developed-by: Stefan Wegrzyn <stefan.wegrzyn@intel.com>
Signed-off-by: Stefan Wegrzyn <stefan.wegrzyn@intel.com>
Signed-off-by: Jedrzej Jagielski <jedrzej.jagielski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>