IPoIB: Add version and firmware info to ethtool reporting

Implement version info as well as report firmware version and bus info
of the underlying IB HW device.

Signed-off-by: Yan Burman <yanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>