dt-bindings: interrupt-controller: qcom,pdc: document qcom,sm4450-pdc

Add SM4450 PDC, which will used in SM4450 DTS.

Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Tengfei Fan <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Rob Herring <[e-mail]>

Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.yaml

···
           - qcom,sdm845-pdc
           - qcom,sdx55-pdc
           - qcom,sdx65-pdc
+          - qcom,sm4450-pdc
           - qcom,sm6350-pdc
           - qcom,sm8150-pdc
           - qcom,sm8250-pdc