drm/i915: make i915 the source of acpi device ids for _DOD

drm/i915: make i915 the source of acpi device ids for _DOD

The graphics driver is supposed to define the DIDL, which are used for
_DOD, not the BIOS. Restore that behaviour.

This is basically a revert of

commit 3143751ff51a163b77f7efd389043e038f3e008e
Author: Zhang Rui <rui.zhang@intel.com>
Date:   Mon Mar 29 15:12:16 2010 +0800

    drm/i915: set DIDL using the ACPI video output device _ADR method return.

which went out of its way to cater to a specific BIOS, setting up DIDL
based on _ADR method. Perhaps that approach worked on that specific
machine, but on the machines I checked the _ADR method invents the
device identifiers out of thin air if DIDL has not been set. The source
for _ADR is also supposed to be the DIDL set by the driver, not the
other way around.

With this, we'll also limit the number of outputs to what the driver
actually has.

A side effect of this change is that the DIDL, and by proxy CADL, will
be initialized in the order of the connector list. That, in turn, has
internal panels in front, ensuring they're included in the DIDL and CADL
lists. Hopefully this ensures the BIOS does not block backlight hotkey
events, thinking the internal panel is off.

v2: do not set ACPI_DEVICE_ID_SCHEME in the device id (Peter Wu)

v3: Rebase

Cc: Peter Wu <peter@lekensteyn.nl>
Cc: Rainer Koenig <Rainer.Koenig@ts.fujitsu.com>
Cc: Jan-Marek Glogowski <glogow@fbihome.de>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
Cc: Paolo Stivanin <paolostivanin@fastmail.fm>
Tested-by: Rainer Koenig <Rainer.Koenig@ts.fujitsu.com>
Tested-by: Paolo Stivanin <paolostivanin@fastmail.fm>
Tested-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
Reviewed-and-tested-by: Peter Wu <peter@lekensteyn.nl>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/9660d29cf310c17bbf4d58c0e09d5b047446e2d5.1479295490.git.jani.nikula@intel.com