ARM: dts: overo: Add support for 4.3'' LCD output

Chestnut43, Gallop43 and Palo43 expansion boards have a ZIF connector
for a 4.3'' LCD. Add a common include file for this configuration, and
use it on relevant expansion boards.

Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>