dt-bindings: arm: amlogic: Add support for the Ugoos AM6

The Ugoos AM6 is based on the Amlogic W400 (G12B) reference design using the
S922X chipset.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

Documentation/devicetree/bindings/arm/amlogic.yaml

@@ -147,6 +147,7 @@ properties:
           - enum:
               - hardkernel,odroid-n2
               - khadas,vim3
+              - ugoos,am6
           - const: amlogic,s922x
           - const: amlogic,g12b