dt-bindings: serial: 8250: Document Tegra234 UART

Add the compatible string for the UART found on the Tegra234 SoC.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Documentation/devicetree/bindings/serial/8250.yaml

@@ -113,9 +113,10 @@ properties:
               - nvidia,tegra30-uart
               - nvidia,tegra114-uart
               - nvidia,tegra124-uart
+              - nvidia,tegra210-uart
               - nvidia,tegra186-uart
               - nvidia,tegra194-uart
-              - nvidia,tegra210-uart
+              - nvidia,tegra234-uart
           - const: nvidia,tegra20-uart
 
   reg: