ARM: dts: sun5i: Fix display pipeline endpoint warnings in DTC

Since most of the display IPs have a single endpoint, having a reg
property, a unit-address and #address-cells and #size-cells will emit a
warning.

Let's remove those.

Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>