etherswitch: Use device_set_desc(f)()

No functional change intended.

MFC after: 1 week

ip17x: fix non-debug build

PR: 278847
Reviewed by: jhibbits
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D45133

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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

etherswitch: Clean up whitespace after IfAPI conversion

Sponsored by: Juniper Networks, Inc.
Fixes: 2e6a8c1ae

Mechanically convert etherswitch drivers to IfAPI

Reviewed by: kd
Sponsored by: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D37813

etherswitch drivers: Remove unused devclass arguments to DRIVER_MODULE.

Remove unused etherswitch_devclass.

Remove unused mdio_devclass.

Remove unused miibus_devclass and miibus_fdt_devclass.

[etherswitch] check if_alloc returns NULL

This patch is cosmetic. It checks if allocation of ifnet structure failed.
It's better to have this check rather than assume positive scenario.

Submitted by: Dmitry Luhtionov <dmitryluhtionov@gmail.com>
Reported by: Dmitry Luhtionov <dmitryluhtionov@gmail.com>

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.

[ip17x] [etherswitch] fdt away and mii hang workaround on ip17x

Add workaround mii access because of rt1310 is hang up on etherswitch mii poll.
And FDT away on arm platform.

Tested:

* wzr2-g300n

Submitted by: Hiroki Mori <yamori813@yahoo.co.jp>
Reviewed by: mizhka
Differential Revision: https://reviews.freebsd.org/D10295

sys/dev: replace comma with semicolon when pertinent.

Uses of commas instead of a semicolons can easily go undetected. The comma
can serve as a statement separator but this shouldn't be abused when
statements are meant to be standalone.

Detected with devel/coccinelle following a hint from DragonFlyBSD.

MFC after: 1 month

[mdio] migrate mdiobus out of etherswitch and into a top-level device of its own.

The mdio driver interface is generally useful for devices that require
MDIO without the full MII bus interface. This lifts the driver/interface
out of etherswitch(4), and adds a mdio(4) man page.

Submitted by: Landon Fuller <landon@landonf.org>
Differential Revision: https://reviews.freebsd.org/D4606

Fix the build with debug enabled and remove a variable used only at switch
initialization, it is nonsense keep it around without futher use.

Add missing includes and remove two unused ones.

Reviewed by: loos
MFC after: 1 week

Bring in a basic ethernet switch driver for the IP17x series of
switches.

These are notably found on some AR71xx based Mikrotik boards.

Submitted by: Luiz Otavio O Souza <loos.br@gmail.com>
Reviewed by: ray