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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

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

net: Update SFF-8024 definitions and strings with values from rev 4.6

This will let ifconfig -v's SFF eeprom read functionality recognize more
module types.

Signed-off-by: Eric Joyner <erj@freebsd.org>

Reviewed by: gallatin@
MFC after: 1 week
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D21041

ifconfig(8): Display extended compliance code string for SFP transceivers

- Updates tables in affected files with new entries from newer spec
revisions of SFF-8472, SFF-8024, and SFF-8636

- Change ifconfig to read and display the extended compliance code for
SFP media if the extended compliance code is not 0. This was being displayed
for QSFP transceivers only, but SFP28 media uses this to report 25G
capability.

Reviewed by: melifaro, sbruno
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D13286

sys: general 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.

No functional change intended.

sys/net*: minor spelling fixes.

No functional change.

* Update SFF-8024 Identifier constants.
* Fix SFF_8436_CC_EXT in SFF-8436 memory map.
* Add SFF-8436/8636 bits (revision compliance/nominal bitrate).
* Do some small style/type fixes.

* Add new net/sff8436.h containing constants used to access
QSFP+ data via i2c inteface. These constants has been taken
from SFF-8436 "QSFP+ 10 Gbs 4X PLUGGABLE TRANSCEIVER" standard
rev 4.8.
* Add support for printing QSFP+ information from 40G NICs
such as Chelsio T5.

This commit does not contain ioctl changes necessary for this
functionality work, there will be another commit soon.

Example:
cxl1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=ec07bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,.....>
ether 00:07:43:28:ad:08
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
media: Ethernet 40Gbase-LR4 <full-duplex>
status: active
plugged: QSFP+ 40GBASE-LR4 (MPO Parallel Optic)
vendor: OEM PN: OP-QSFP-40G-LR4 SN: 20140318001 DATE: 2014-03-18
module temperature: 64.06 C voltage: 3.26 Volts
lane 1: RX: 0.47 mW (-3.21 dBm) TX: 2.78 mW (4.46 dBm)
lane 2: RX: 0.20 mW (-6.94 dBm) TX: 2.80 mW (4.47 dBm)
lane 3: RX: 0.18 mW (-7.38 dBm) TX: 2.79 mW (4.47 dBm)
lane 4: RX: 0.90 mW (-0.45 dBm) TX: 2.80 mW (4.48 dBm)

Tested on: Chelsio T5
Tested on: Mellanox/Huawei passive/active cables/transceivers.
MFC after: 2 weeks
Sponsored by: Yandex LLC

* Use standard net/sff8472.h header for sff bits and offsets.
* Convert sff_8472_id to 'const char *' to please clang.

Pointed by: np

Convert #defines to enums so that the values are visible in the debugger.

Requested by: gibbs
MFC after: 2 weeks

Add constants for use in interrogating various fiber and copper connectors
most often used with network interfaces.

The SFF-8472 standard defines the information that can be retrieved
from an optic or a copper cable plugged into a NIC, most often
referred to as SFP+. Examples of values that can be read
include the cable vendor's name, part number, date of manufacture
as well as running data such as temperature, voltage and tx
and rx power.

Copious comments on how to use these values with an I2C interface
are given in the header file itself.

MFC after: 2 weeks