PCI/VGA: Move vgaarb to drivers/pci

The VGA arbiter is really PCI-specific and doesn't depend on any GPU
things. Move it to the PCI subsystem.

Note that misc_init() must be called before vga_arb_device_init(). These
are both subsys_initcalls, so this ordering depends on the link order,
which is determined by drivers/Makefile:

obj-y += pci/
obj-y += char/ <-- misc_init()
obj-y += gpu/ <-- vga_arb_device_init() (before this commit)

The drivers/pci/ subsys_initcalls are called *before* misc_init(), so
convert vga_arb_device_init() to subsys_initcall_sync(), which is called
after *all* subsys_initcalls.

Link: https://lore.kernel.org/r/20220224224753.297579-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drm: Replace HTTP links with HTTPS ones

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200719171428.60470-1-grandmaster@al2klimov.de

vgaarbiter: rst-ifiy and polish kerneldoc

Move the documentation into Documentation/gpu, link it up and pull in
the kernel doc.

No actual text changes except that I did polish the kerneldoc a bit,
especially for vga_client_register().

v2: Remove some rst from vga-switcheroo.rst that I don't understand,
but which seems to be the reason why the new vgaarbiter.rst sometimes
drops out of the sidebar index.

v3: Drop one level of headings and clarify the vgaarb one a bit.

v4: Fix some typos (Sean).

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471034937-651-20-git-send-email-daniel.vetter@ffwll.ch