ARM: OMAP: overo: use new display drivers

Use the new display drivers for OMAP3 Overo 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.

Note that the LCD add-on boards for lcd43 and lcd35 use the same GPIOs
for the panels. This means that both panel devices cannot be probed at
the same time.

DT will handle this correctly, i.e. the DT data will contain the panel
device only for the add-on board that is attached. However, for the
board file we need a hackish solution: We parse the kernel boot command
line, and see whether lcd43 or lcd35 is set as a default display, and
add the given one. Or, if neither is given, default to lcd43.

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