dt-bindings: arm: fsl: Add NXP S32N79 SoC and RDB board

Add device tree binding documentation for the NXP S32N79 automotive SoC
and the S32N79 Reference Design Board (S32N79-RDB).

The S32N79 is an automotive-grade SoC featuring eight ARM Cortex-A78AE
cores organized for high-performance networking and gateway applications
in vehicles.

Co-developed-by: Larisa Grigore <larisa.grigore@nxp.com>
Signed-off-by: Larisa Grigore <larisa.grigore@nxp.com>
Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>

Author: Ciprian Marian Costea

Documentation/devicetree/bindings/arm/fsl.yaml

@@ -1869,6 +1869,12 @@ properties:
               - fsl,s32v234-evb           # S32V234-EVB2 Customer Evaluation Board
           - const: fsl,s32v234
 
+      - description: S32N79 based Boards
+        items:
+          - enum:
+              - nxp,s32n79-rdb
+          - const: nxp,s32n79
+
       - description: Traverse LS1088A based Boards
         items:
           - enum: