MFC r289568, r300676, r300677, r300719, r300720 and r300721:
Implement LinuxKPI module parameters as SYSCTLs.

The bool module parameter is no longer supported, because there is no
equivalent in FreeBSD 10-stable. These are converted into "int" type.

There are two macros available which control the behaviour of the
LinuxKPI module parameters:

- LINUXKPI_PARAM_PARENT allows the consumer to set the SYSCTL parent
where the modules parameters will be created.

- LINUXKPI_PARAM_PREFIX defines a parameter name prefix, which is
added to all created module parameters.

The LinuxKPI module parameters also have a permissions value.
If any write bits are set we are allowed to modify the module
parameter runtime. Reflect this when creating the static SYSCTL
nodes.

The module_param_call() function is no longer supported.

Sponsored by: Mellanox Technologies

MFC r312881:
Add support for device surprise removal and other PCI errors.

- When device disappears from PCI indicate error device state and:
1) Trigger command completion for all pending commands
2) Prevent new commands from executing and return:
- success for modify and remove/cleanup commands
- failure for create/query commands
3) When reclaiming pages for a device in error state don't ask FW to
return all given pages, just release the allocated memory

Sponsored by: Mellanox Technologies

MFC r312880:
Wait for all VFs pages to be reclaimed before closing EQ pages.

Sponsored by: Mellanox Technologies

MFC r305867:
Update the MLX5 core module:
- Add new firmware commands and update existing ones.
- Add more firmware related structures and update existing ones.
- Some minor fixes, like adding missing \n to some prints.

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