drm/i915: Exercise filling the top/bottom portions of the global GTT

Same test as previously for the per-process GTT instead applied to the
global GTT.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-29-chris@chris-wilson.co.uk
1 file changed