ARM: dts: Prepare Realtek RTD1195 and MeLE X1000

Add Device Trees for Realtek RTD1195 SoC and MeLE X1000 TV box.

Reuse the existing RTD1295 watchdog compatible for now.

Reviewed-by: Rob Herring <robh@kernel.org>
[AF: Fixed r-bus size, fixed GIC, updated memreserve & memory]
Signed-off-by: Andreas Färber <afaerber@suse.de>