mlx4_core: Check firmware command interface revision

mlx4_core: Check firmware command interface revision

HCA firmware with incompatible changes to the FW commmand interface is
coming soon.  Add a check of the interface revision during
initialization and bail out if the firmware advertises a revision that
the driver doesn't know about.  This will avoid strange failures later
if the driver goes on using the wrong interface revision.

Signed-off-by: Roland Dreier <rolandd@cisco.com>