drm/i915: Don't complain about lack of ACPI video bios

Another CI fail we have for no reason. Totally unjustified since
nothing fails at all.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445590806-23886-1-git-send-email-daniel.vetter@ffwll.ch


Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>