mlxsw: spectrum_fid: Set NVE flood profile as part of FID configuration

The NVE flood profile is used for determining of offset applied to KVD
address for NVE flood. We currently do not set it, leaving it at the
default value of 0. That is not an issue: all the traffic-type-to-offset
mappings (as configured by SFFP) default to offset of 0. This is what we
need anyway, as mlxsw only allocates a single KVD entry for NVE underlay.

The field is only relevant on Spectrum-2 and above. So to be fully
consistent, we should split the existing controlled ops to Spectrum-1 and
Spectrum>1 variants, with only the latter setting the field. But that seems
like a lot of overhead for a single field whose meaning is "everything is
the default". So instead pretend that the NVE flood profile does not exist
in the controlled flood mode, like we have so far, and only set it when
flood mode is CFF.

Setting this at all serves dual purpose. First, it is now clear which
profile belongs to NVE, because in the CFF mode, we have multiple users.
This should prevent bugs in flood profile management. Second, using
specifically non-zero value means there will be no valid uses of the
profile 0, which we can therefore use as a sentinel.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>