[openib-general] MT25218 (aka Arbel memfree) support

[Roland Dreier]

    Michael> What would be the best way to organise this code?  I
    Michael> guess could be two thinkable ways to do this:

    Michael> 1. Add the functionality to the mthca module, use a
    Michael> run-time flag to describe hardware differences.  Thus,
    Michael> the same module will handle devices of all types.

I've already started adding some memfree support ot the mthca module
(following this approach).  So far the code does initialization
through MAP_FA and RUN_FW, and calls QUERY_DEV_LIM.

By the way, there's no need for a runtime flag, the PCI device ID is
sufficient to distinguish Tavor mode from Arbel mode.

 - Roland