mlxsw: reg: Activate Bloom filter

Now that mlxsw driver handles all aspects of updating
the Bloom filter mechanism, set bf_bypass value to false
and allow HW to use Bloom filter.

Signed-off-by: Nir Dotan <nird@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>