dt-bindings: arm: sunxi: document Tanix TX1 name

dt-bindings: arm: sunxi: document Tanix TX1 name

The Tanix TX1 is a tiny TV box with the Allwinner H313 SoC, a lower bin
version of the Allwinner H616. It comes with no SD card slot or Ethernet
port.

Add the board/SoC compatible string pair to the list of known boards.
Since the H313 does not look different from a software point of view,
we keep the H616 compatible string.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240418104942.1556914-2-andre.przywara@arm.com
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>