dt-bindings: tegra: Add Shield TV device tree binding documentation

Add the device tree binding documentation for NVIDIA Shield TV.
Signed-off-by: Mark Zhang <markz@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Documentation/devicetree/bindings/arm/tegra.yaml

@@ -87,9 +87,11 @@ properties:
           - const: nvidia,tegra124
       - items:
           - enum:
+              - nvidia,darcy
               - nvidia,p2371-0000
               - nvidia,p2371-2180
               - nvidia,p2571
+              - nvidia,p2894-0050-a08
           - const: nvidia,tegra210
       - items:
           - enum: