dt-bindings: arm: amlogic: add Odroid-N2 binding

Add compatible for the Amlogic G12B (S922X) SoC based Odroid-N2 SBC
from HardKernel.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

Documentation/devicetree/bindings/arm/amlogic.yaml

@@ -137,6 +137,8 @@ properties:
 
       - description: Boards with the Amlogic Meson G12B S922X SoC
         items:
+          - enum:
+              - hardkernel,odroid-n2
           - const: amlogic,g12b
 
 ...