drm/i915: Stop trying to use ACPI lid status to determine LVDS connection.

I've been getting more and more quirk reports about this.  It seems
clear at this point that other OSes are not using this for determining
whether the integrated panel should be turned on, and it is not
reliable for doing so.  Better to light up an unintended panel than to
not light up the only usable output on the system.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>