arm64: dts: allwinner: h6: Add Video Engine node

This adds the Video engine node for H6. It can use whole DRAM range so
there is no need for reserved memory node.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>