mlxsw: spectrum_fid: Rename mlxsw_sp_fid_vni_op()

After the previous patch, all the callers of the function pass arguments
extracted from the FID structure itself. Reduce the arguments list by
simply passing the FID structure itself.

This makes the function more generic as it can be easily extended to
edit any FID attributes. Rename it to mlxsw_sp_fid_edit_op() to reflect
that.

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