net/mlx5e: Schedule overflow check work to mlx5e workqueue

This is done in order to ensure that work will not run after the cleanup.

Fixes: ef9814de ('net/mlx5e: Add HW timestamping (TS) support')
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>