MFC r305868:
mlx5en: Separate the sendqueue from using the mlx5e_channel structure.

This change allows for reusing the transmit path for so called
rate limited senqueues. While at it optimise some pointer lookups
in the fast path.

Sponsored by: Mellanox Technologies

MFC r292838:
Add support for CQE zipping. CQE zipping reduces PCI overhead by
coalescing and zipping multiple CQEs into a single merged CQE. The
feature is enabled by default and can be disabled by a sysctl.

Implementing this feature mlx5_cqwq_pop() has been separated from
mlx5e_get_cqe().

Submitted by: Mark Bloch <markb@mellanox.com>
Differential Revision: https://reviews.freebsd.org/D4598
Sponsored by: Mellanox Technologies

MFC r290650, r290709, r291067, r291068, r291069 and r291070:
Add mlx5 and mlx5en driver(s) for ConnectX-4 and ConnectX-4LX cards
from Mellanox Technologies. The current driver supports ethernet
speeds up to and including 100 GBit/s. Infiniband support will be
done later.

The code added is not compiled by default, which will be done by a
separate commit.

Sponsored by: Mellanox Technologies
Differential Revision: https://reviews.freebsd.org/D4177
Differential Revision: https://reviews.freebsd.org/D4178
Differential Revision: https://reviews.freebsd.org/D4179
Differential Revision: https://reviews.freebsd.org/D4180

Add mlx5 and mlx5en driver(s) for ConnectX-4 and ConnectX-4LX cards
from Mellanox Technologies. The current driver supports ethernet
speeds up to and including 100 GBit/s. Infiniband support will be
done later.

The code added is not compiled by default, which will be done by a
separate commit.

Sponsored by: Mellanox Technologies
MFC after: 2 weeks