dt-bindings: arm: amlogic: add X96-AIR bindings

Add board bindings for the Amediatech X96-AIR STB which ships with
model variants distiguished by Ethernet configuration: models using
an external Gigabit PHY have a -gbit suffix, while models using an
internal 10/100 PHY have no suffix.
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20220112022713.25962-3-christianshewitt@gmail.com

Documentation/devicetree/bindings/arm/amlogic.yaml

@@ -170,6 +170,8 @@ properties:
       - description: Boards with the Amlogic Meson SM1 S905X3/D3/Y3 SoC
         items:
           - enum:
+              - amediatech,x96-air
+              - amediatech,x96-air-gbit
               - bananapi,bpi-m5
               - hardkernel,odroid-c4
               - hardkernel,odroid-hc4