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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

vt: export RGB offsets with FBIO_GETRGBOFFS

Add a new ioctl to vt to make it possible to export RGB offsets
set by vt drivers. This is needed to fix colors on X and Mesa
on some machines, especially on modern PowerPC64 BE ones.

With the appropriate changes in SCFB, to use this ioctl to find
out the correct RGB offsets, this fixes wrong colors on Talos II
and Blackbird, when used with their built-in video cards.

Reviewed by: alfredo
Sponsored by: Instituto de Pesquisas Eldorado (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D29000

Remove "All Rights Reserved" from FreeBSD Foundation sys/ copyrights

These ones were unambiguous cases where the Foundation was the only
listed copyright holder (in the associated license block).

Sponsored by: The FreeBSD Foundation

vt(4): Use default VGA palette

Before this change, the VGA palette was configured to match the shell
palette (e.g. color #1 was red). There was one glitch early in boot when
the vt(4)'s VGA palette was loaded: the loader's logo would switch from
red to blue. Likewise for the "Booting..." message switching from blue
to red. That's because the loader's logo was drawed with the default VGA
palette where a few colors are swapped compared to the shell palette
(e.g. blue <-> red).

This change configures the default VGA palette during initialization and
converts input's colors from shell to VGA palette index.

There should be no visible changes, except the loader's logo which will
keep its original color.

Reviewed by: eadler

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.

vt(4): Colors are indexed against a console palette, not a VGA palette

Rename vt_generate_vga_palette() to vt_generate_cons_palette() and
change it to build a palette where the color index is the same than in
terminal escape codes, not the VGA index. That's what TCHAR_CREATE()
uses and passes to vt(4).

The main differences between both orders are:
o Blue and red are swapped (1 <-> 4)
o Yellow and cyan are swapped (3 <-> 6)

The problem remained unnoticed, because the RGB bit indexes passed to
vt_generate_vga_palette() were reversed. This inversion was cancelled
by the colors inversions in the generated palette. For instance, red
(0xff0000) and blue (0x0000ff) have bytes in opposite order, but were
swapped in the palette. But after changing the value of blue (see last
paragraph), the modified color was in fact the red one.

This commit includes a fix to creator_vt.c, submitted by Nathan
Whitehorn: fb_cmsize is set to 16. Before this, the generated palette
would be overwritte. This fixes colors on sparc64 with a Creator3D
adapter.

While here, tune the palette to better match console colors and improve
the readability (especially the dark blue).

Submitted by: nwhitehorn (fix to creator_vt.c)
MFC after: 1 week

Merge VT(9) project (a.k.a. newcons).

Reviewed by: nwhitehorn
MFC_to_10_after: re approval

Sponsored by: The FreeBSD Foundation