mlxsw: spectrum: Bump required firmware version

MC-aware mode was introduced to mlxsw in commit 7b819530 ("mlxsw: spectrum:
Configure MC-aware mode on mlxsw ports") and fixed up later in commit
3a3539cd ("mlxsw: spectrum_buffers: Set up a dedicated pool for BUM
traffic"). As the final piece of puzzle, a firmware issue whereby a wrong
priority was assigned to BUM traffic was corrected in FW version 13.1703.4.
Therefore require this FW version in the driver.

Fixes: 7b819530 ("mlxsw: spectrum: Configure MC-aware mode on mlxsw ports")
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>