ARM: clps711x: autcpu12: Move LCD DPOT definitions to board file

We do not have driver for Up/Down digital potentiometer (DPOT), so
just define pins as GPIOs and export these pins to user.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Olof Johansson <olof@lixom.net>