dt-bindings: hwmon: Add MPS mp9941

Add support for MPS mp9941 controller

Acked-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Noah Wang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>

Documentation/devicetree/bindings/trivial-devices.yaml

···
           - mps,mp2993
             # Monolithic Power Systems Inc. multi-phase hot-swap controller mp5990
           - mps,mp5990
+            # Monolithic Power Systems Inc. digital step-down converter mp9941
+          - mps,mp9941
             # Monolithic Power Systems Inc. synchronous step-down converter mpq8785
           - mps,mpq8785
             # Temperature sensor with integrated fan control