To be aligned with the rest of the drivers, expose FW version under "fw"
keyword in devlink dev info, in addition to the existing "fw.version",
which is currently Mellanox-specific.

devlink output before:
       running:
         fw.version 30.2008.2018
after:
       running:
         fw.version 30.2008.2018
         fw 30.2008.2018
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>