powerpc/85xx: add DIU support to the Freecale P1022DS reference board

The Freescale P1022DS has an on-chip video controller called the DIU, and a
driver for this device already exists.  Update the platform file for the
P1022DS reference board to enable the driver, and update the defconfig for
Freescale MPC85xx boards to add the driver.

[Edited to resolve header add/add conflict and drop #define DEBUG.
-- broonie]

Signed-off-by: Timur Tabi <timur@freescale.com>
Acked-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>