mlxsw: core: Move basic trap group initialization from spectrum.c

Instead of initializing the trap groups used by core in spectrum.c
over op, do it directly in core.c

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>