mlxsw: spectrum_fid: Store 'bridge_type' as part of FID family

Currently, 'bridge_type' is an attribute of 'struct mlxsw_sp_flood_table',
which is defined per FID family. Instead, it can be an attribute of
'struct mlxsw_sp_fid_family' as all flood tables in the same family are of
the same type. This change will ease the configuration of
'SFMR.flood_bridge_type' which will be added in the next patch.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>