sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

sfxge: clean up empty lines in .c and .h files

sys/dev: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

sfxge(4): cleanup: update copyright to 2016

Sponsored by: Solarflare Communications, Inc.
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D6509

sfxge: add 7xxx NICs family support

Support 7xxx adapters including firmware-assisted TSO and VLAN tagging:

- Solarflare Flareon Ultra 7000 series 10/40G adapters:
- Solarflare SFN7042Q QSFP+ Server Adapter
- Solarflare SFN7142Q QSFP+ Server Adapter

- Solarflare Flareon Ultra 7000 series 10G adapters:
- Solarflare SFN7022F SFP+ Server Adapter
- Solarflare SFN7122F SFP+ Server Adapter
- Solarflare SFN7322F Precision Time Synchronization Server Adapter

- Solarflare Flareon 7000 series 10G adapters:
- Solarflare SFN7002F SFP+ Server Adapter

Support utilities to configure adapters and update firmware.

The work is done by Solarflare developers
(Andy Moreton, Andrew Lee and many others),
Artem V. Andreev <Artem.Andreev at oktetlabs.ru> and me.

Sponsored by: Solarflare Communications, Inc.
MFC after: 2 weeks
Causually read by: gnn
Differential Revision: https://reviews.freebsd.org/D2618

sfxge: add common code support for changing TX queue pace

To delay packets from a particular TX queue by a particular time, write a value
into the TX Pace table s.t. pace time <= TX Pace Clock Period * (2 ^ pace value)
- the TX pace clock is 1/13 of the system clock, so its period should be 104 or
52 ns depending on whether turbo mode is active.

EFX_TX_PACE_CLOCK_BASE added by me.

Submitted by: Mark Spender <mspender at solarflare.com>
Sponsored by: Solarflare Communications, Inc.
Approved by: gnn (mentor)

sfxge: Add $FreeBSD$ tags to common code files.

Requested by: bz

Add the sfxge(4) device driver, providing support for 10Gb Ethernet adapters
based on Solarflare SFC9000 family controllers. The driver supports jumbo
frames, transmit/receive checksum offload, TCP Segmentation Offload (TSO),
Large Receive Offload (LRO), VLAN checksum offload, VLAN TSO, and Receive Side
Scaling (RSS) using MSI-X interrupts.

This work was sponsored by Solarflare Communications, Inc.

My sincere thanks to Ben Hutchings for doing a lot of the hard work!

Sponsored by: Solarflare Communications, Inc.
MFC after: 3 weeks