mlxsw: spectrum_fid: Move mlxsw_sp_fid_flood_table_init() up

Move the function to the point where it will need to be to be visible for
the 802.1d ops.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/aef09e26b0c2dd077531e665d7135b300bdaf0a8.1701183892.git.petrm@nvidia.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>