net/mlx5e: Implement ethtool hardware timestamping statistics

Feed driver statistics counters related to hardware timestamping to
standardized ethtool hardware timestamping statistics group.

Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Link: https://lore.kernel.org/r/20240403212931.128541-5-rrameshbabu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>