ARM: dts: sun8i: v3s: add DMA controller to v3s dts

The Allwinner V3s and V3 feature a DMA controller.
This commit adds it to the V3s dtsi.

Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20210514134405.2097464-2-t.schramm@manjaro.org