mlxsw: Enforce firmware version for Spectrum-3

In a fashion similar to the other Spectrum systems, enforce a specific
firmware version for Spectrum-3 so that the driver and firmware are
always in sync with regards to new features.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>