net/mlx5: Avoid generating event after PPS out in Real time mode

When in Real-time mode, HW clock is synced with the PTP daemon. Hence
driver should not re-calibrate the next pulse (via MTPPSE repetitive
events mechanism).

This patch arms repetitive events only in free-running mode.

Fixes: 432119de

 ("net/mlx5: Add cyc2time HW translation mode support")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Eran Ben Elisha <eranbe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>