drm/i915: BDW: Adding Reserved PCI IDs.

These PCI IDs are reserved on BSpec and can be used at any time in the future.
So let's add this now in order to avoid issues that we already faced on previous
platforms, like finding out about new ids when user reported accelaration weren't
enabled.

Cc: stable@vger.kernel.org
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>