dt-bindings: arm: ti: Add bindings for Siemens IOT2050 boards

These boards are based on AM6528 GP and AM6548 HS SOCs.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/173ce7d928ed9f352af7673dd44c6c76a1466eb5.1615473223.git.jan.kiszka@siemens.com

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

@@ -23,6 +23,8 @@ properties:
         items:
           - enum:
               - ti,am654-evm
+              - siemens,iot2050-basic
+              - siemens,iot2050-advanced
           - const: ti,am654
 
       - description: K3 J721E SoC