[openib-general] enable GSO over IPoIB

[Roland Dreier]

    Shirley> If we only support GSO enablement in ethtool, there is no
    Shirley> problem. What I meant is anything related to MAC address
    Shirley> in ethtool utility needs to be updated for IB device.

    Shirley> Do you like the idea to add ethtool support in IPoIB? Do
    Shirley> you want me to work on this?

It seems like a good thing at first blush, athough I haven't thought
through all the implications.  But yes, being able to dump info and
set options via ethtool seems like a good idea.  I assume there will
also be ethtool changes to merge into the upstream ethtool sources.

 - R.