dt-bindings: ARM: tegra: Add Acer Iconia Tab A500

Add a binding for the Tegra20-based Acer Iconia Tab A500 tablet device.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Documentation/devicetree/bindings/arm/tegra.yaml

@@ -34,6 +34,9 @@ properties:
               - toradex,colibri_t20-iris
           - const: toradex,colibri_t20
           - const: nvidia,tegra20
+      - items:
+          - const: acer,picasso
+          - const: nvidia,tegra20
       - items:
           - enum:
               - nvidia,beaver