arm64: dts: allwinner: a64: Add Video Engine node

This adds the Video Engine node for the A64. Since it can map the whole
DRAM range, there is no particular need for a reserved memory node
(unlike platforms preceding the A33).

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