ARM: omap3-n900.dts: add display information

Add DT data for OMAP3 N900 board. The board has the following displays:

lcd: LCD panel connected to OMAP's SDI output
tv: analog svideo

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Tested-by: Sebastian Reichel <sre@debian.org>
Acked-by: Tony Lindgren <tony@atomide.com>