drm/i915: Ivy Bridge has split display and pipe control

Ivy Bridge has a similar split display controller to Sandy Bridge, so
use HAS_PCH_SPLIT.  And gen7 also has the pipe control instruction, so
use HAS_PIPE_CONTROL as well.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>