This was forgotten in

commit d351f6d9
Author: Francisco Jerez <currojerez@riseup.net>
Date:   Fri May 29 16:44:15 2015 +0300

    drm/i915: Add SCRATCH1 and ROW_CHICKEN3 to the register whitelist.
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>