arm64: dts: allwinner: a64: enable ANX6345 bridge on Teres-I

Teres-I has an anx6345 bridge connected to the RGB666 LCD output, and
the I2C controlling signals are connected to I2C0 bus.

Enable it in the device tree, and enable the display engine, video mixer
and tcon0 as well.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>