ARM: dts: exynos: remove display-port node from Arndale

Arndale boards have wires for DSI and eDP panels, but in-kernel support
for eDP panels is broken for long time and breaks display support even on
boards with DSI panels.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>