dt-bindings: arm: qcom: Document SM4450 SoC and boards

Document the SM4450 SoC binding and also the boards using it.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Tengfei Fan <quic_tengfan@quicinc.com>
Link: https://lore.kernel.org/r/20230731080043.38552-3-quic_tengfan@quicinc.comSigned-off-by: Bjorn Andersson <andersson@kernel.org>

Documentation/devicetree/bindings/arm/qcom.yaml

@@ -72,6 +72,7 @@ description: |
         sdx65
         sdx75
         sm4250
+        sm4450
         sm6115
         sm6115p
         sm6125
@@ -903,6 +904,11 @@ properties:
           - const: qcom,qrb4210
           - const: qcom,sm4250
 
+      - items:
+          - enum:
+              - qcom,sm4450-qrd
+          - const: qcom,sm4450
+
       - items:
           - enum:
               - fxtec,pro1x