dt-bindings: arm: ti: Add compatible for AM642-based TQMaX4XxL SOM family and carrier board

For now only the MBaX4Xx carrier board is defined.
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/e4283d6af59c77d2f690e070eb948dd9142a2276.1690463382.git.matthias.schiffer@ew.tq-group.comSigned-off-by: Nishanth Menon <nm@ti.com>

Documentation/devicetree/bindings/arm/ti/k3.yaml

@@ -72,6 +72,13 @@ properties:
           - const: phytec,am64-phycore-som
           - const: ti,am642
 
+      - description: K3 AM642 SoC on TQ-Systems TQMaX4XxL SoM
+        items:
+          - enum:
+              - tq,am642-tqma6442l-mbax4xxl # MBaX4XxL base board
+          - const: tq,am642-tqma6442l
+          - const: ti,am642
+
       - description: K3 AM654 SoC
         items:
           - enum: