mlxsw: spectrum_router: Use extack in mlxsw_sp~_rif_ipip_lb_configure()

In commit 26029225 ("mlxsw: spectrum_router: Propagate extack
further"), the mlxsw_sp_rif_ops.configure callback got a new argument,
extack. However the callbacks that deal with tunnel configuration,
mlxsw_sp1_rif_ipip_lb_configure() and mlxsw_sp2_rif_ipip_lb_configure(),
were never updated to pass the parameter further. Do that now.

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