net/mlx5e: SHAMPO, Add header-only ethtool counters for header data split

Count the number of header-only packets and bytes from SHAMPO.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20240603212219.1037656-12-tariqt@nvidia.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>