sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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: 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.

net80211: ieee80211_ratectl*: switch to reusable KPI

Replace various void * / int argument combinations with common structures:
- ieee80211_ratectl_tx_status for *_tx_complete();
- ieee80211_ratectl_tx_stats for *_tx_update();

While here, improve amrr_tx_update() for a bit:
1. In case, if receiver is not known (typical for Ralink USB drivers),
refresh Tx rate for all nodes on the interface.
2. There was a misuse:
- otus(4) sends non-decreasing counters (as originally intended);
- but ural(4), rum(4) and run(4) are using 'read & clear' registers
to obtain statistics for some period of time (and those 'last period'
values are used as arguments for tx_update()). If arguments are not big
enough, they are just discarded after the next call.

Fix: move counting into *_tx_update()
(now otus(4) will zero out all node counters after every tx_update() call)

Tested with:
- Intel 3945BG (wpi(4)), STA mode.
- WUSB54GC (rum(4)), STA / HOSTAP mode.
- RTL8188EU (urtwn(4)), STA mode.

Reviewed by: adrian
Differential Revision: https://reviews.freebsd.org/D8037

Move counter.h include into ieee80211_freebsd.h. Should fix build.

Submitted by: Zilvinas Valinskas <zilvinas.valinskas gmail.com>

Add two counters to ieee80211com, that will be used to count transmission
or receive errors that can't be associated with any vap.

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Convert malloc/free back to #define's, as part of OS portability work.

DragonflyBSD uses the FreeBSD wireless stack and drivers. Their malloc()
API is named differently, so they don't have userland/kernel symbol
clashes like we do (think libuinet.)

So, to make it easier for them and to port to other BSDs/other operating
systems, start hiding the malloc specific bits behind defines in
ieee80211_freebsd.h.

DragonflyBSD can now put these portability defines in their local
ieee80211_dragonflybsd.h.

This should be a great big no-op for everyone running wifi.

TODO:

* kill M_WAITOK - some platforms just don't want you to use it
* .. and/or handle it returning NULL rather than waiting forever.
* MALLOC_DEFINE() ?
* Migrate the well-known malloc names (eg M_TEMP) to net80211
namespace defines.

Provide includes that are needed in these files, and before were read
in implicitly via if.h -> if_var.h pollution.

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Some device drivers calculate various timing related things based on
the currently selected rate. The calculations of course need a valid
rate. To make that possible before any call to node_rate() is done,
initialize ni_txrate on none_node_init() calls.

MFC after: 1 week

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Fix an undefined behaviour if the desired ratectl algo is not available.
This can happen if the algos are built as modules but are not loaded. If
the selected ratectl algo is not available, try to load it (The load
module functions does nothing currently). Add a dummy ratectl algo which
always selects the first available rate. Use that one if the desired algo
is not available.

MFC after: 1 week