ARM: dts: sun8i-a83t: Remove empty CSI port

The empty CSI port triggers a dt-validate warning. Let's align with the
other DTSI and remove it entirely, expecting the DTS to fill it.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Jernej Skrabec <jernej.skrabec@siol.net>
Link: https://lore.kernel.org/r/20210114113538.1233933-14-maxime@cerno.tech