ARM: OMAP: igep0020: use new display drivers

Use new display drivers for igep0020 board.

The new OMAP display drivers were merged for 3.11, and we can now change
the board files to use the new ones and phase out the old ones.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>