net/mlx5e: xsk: Set napi_id to support busy polling

xdp_rxq_info_reg should get the actual napi_id, not 0, in order to
support socket busy polling properly.

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>