net/mlx5e: Move dynamic interrupt coalescing code to include/linux

This move allows drivers to add private structure elements to track the
number of packets, bytes, and interrupts events per ring.  A driver
also defines a workqueue handler to act on this collected data once per
poll and modify the coalescing parameters per ring.

Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Acked-by: Tal Gilboa <talgi@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>