ARM: dts: n900: Add aliases for lcd and tvout displays

When both lcd and tv are enabled, the order in which they will be probed is
unknown, so it might happen (and it happens in reality) that tv is
configured as display0 and lcd as display1, which results in nothing
displayed on lcd, as display1 is disabled by default.

Fix that by providing correct aliases for lcd and tv

Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>