drm/i915: Reorder i915_params struct.

Move all the bool variables to the end as per the comment.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450436898-20408-3-git-send-email-joonas.lahtinen@linux.intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>