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

Similar commit in current:
(cherry picked from commit 95ee2897e98f)

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

(cherry picked from commit 4d846d260e2b9a3d4d0a701462568268cbfe7a5b)

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.

I thank all developers and contributors for pc98.

Relnotes:	yes

implemented with macros. This patch improves code readability. Reasoning
behind vidd_* is a sort of "video discipline".

List of macros is supposed to be complete--all methods of video_switch
ought to have their respective macros from now on.

Functionally, this code should be no-op. My intention is to leave current
behaviour of touched code as is.

No objections:	rwatson
Silence on:	freebsd-current@
Approved by:	cognet

themselves.

Reviewed by:	nate, peter, warner, robert
Approved by:	re (ken)