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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

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.

Turns out the AR933x looks like the AR7240/AR7241 switch as far as VLAN
configuration is concerned.

So, remove the now-erroneous comment.

Tested:

* AR9331 - Carambola2, with transmitting dot1q tagged packets around.

Commit 802.1q configuration support for the AR8327.

This is slightly different to the other switches - the VLAN table
(VTU) programs in the vlan port mapping /and/ the port config
(tagged, untagged, passthrough, any.)

So:

* Add VTU operations to program the VTU (vlan table)
* abstract out the mirror-disable function so it's .. well, a function.
* setup the port to have a dot1q configuration for dot1q - the
port security is VLAN (not per-port VLAN) and requires an entry
in the VLAN table;
* add set_dot1q / get_dot1q to program the VLAN table;
* since the tagged/untagged ports are now programmed into the VTU,
rather than global - plumb the ports /and/ untagged ports bitmaps
through the arswitch API.

Tested:

* AP135 - QCA9558 SoC + AR8327N switch

Methodise a couple more of the VLAN methods.

Add per-port vlan support for the AR8327.

All the per-port support is really doing is applying a port visibility
mask to each of the switchports. Everything still look like a single
portgroup (vlan id 1), but the per-port visibility mask is modified.

Whilst I'm here, also add some initial dot1q support - the pvid stuff
is doing the right thing, but it's not useful without the rest of
the VLAN table programming.

It's enough for me to be able to use the LAN/WAN port distinction
on the AP135, where there isn't (for now!) a dedicated PHY for the
"WAN" port.

Tested:

* AP135, QCA9558 SoC + AR8327 switch

Methodize the arswitch VLAN routines.

These differ per chipset family in subtle and evil ways.

It becomes very noticable on the AR8327 where the layout is just plain
wrong.

- Provide necessary includes, that before came via if.h pollution.
- Remove unnecessary ones.

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Add a big, big note to the vlan code that it needs to be taught
about the new VLAN options for the AR9340 and AR8327 chips.

Add the support for 802.1q and port based vlans for arswitch.

Tested on: RB450G (standalone ar8316), RSPRO (standalone ar8316) and
TPLink MR-3220 (ar724x integrated switch).

Approved by: adrian (mentor)
Obtained from: zrouter