ARM: dts: logicpd-torpedo-baseboard: Reduce video regulator chatter

The dss driver wants two regulators or it dump some splat while
initializing.  This patch adds a reference to the second regulator
which to avoid the warnings that the regulator is missing.

Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>