arm64: dts: allwinner: teres-i: Add missing reg

The anx6345 bridge mandates that the input port is named port@0. Since
we have a unit-address, this implies that we need a reg property with
the same value, but it was found to be missing in the Teres-I device
tree. Make sure it's there.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20210901091852.479202-52-maxime@cerno.tech