dt-bindings: watchdog: improve QCOM compatible parsing for modern chips

Parse compatible as expected for modern QCOMs.

Fixes warnings as:
arch/arm64/boot/dts/qcom/sdm845-oneplus-fajita.dt.yaml: watchdog@17980000: compatible: ['qcom,apss-wdt-sdm845', 'qcom,kpss-wdt'] is too long
        From schema: Documentation/devicetree/bindings/watchdog/qcom-wdt.yaml
arch/arm64/boot/dts/qcom/sdm845-oneplus-fajita.dt.yaml: watchdog@17980000: compatible: Additional items are not allowed ('qcom,kpss-wdt' was unexpected)
        From schema: Documentation/devicetree/bindings/watchdog/qcom-wdt.yaml

Signed-off-by: David Heidelberg <david@ixit.cz>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220111212310.97566-1-david@ixit.cz
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Documentation/devicetree/bindings/watchdog/qcom-wdt.yaml

@@ -14,22 +14,27 @@ allOf:
 
 properties:
   compatible:
-    enum:
-      - qcom,apss-wdt-qcs404
-      - qcom,apss-wdt-sc7180
-      - qcom,apss-wdt-sc7280
-      - qcom,apss-wdt-sdm845
-      - qcom,apss-wdt-sdx55
-      - qcom,apss-wdt-sm6350
-      - qcom,apss-wdt-sm8150
-      - qcom,apss-wdt-sm8250
-      - qcom,kpss-timer
-      - qcom,kpss-wdt
-      - qcom,kpss-wdt-apq8064
-      - qcom,kpss-wdt-ipq4019
-      - qcom,kpss-wdt-ipq8064
-      - qcom,kpss-wdt-msm8960
-      - qcom,scss-timer
+    oneOf:
+      - items:
+          - enum:
+              - qcom,apss-wdt-qcs404
+              - qcom,apss-wdt-sc7180
+              - qcom,apss-wdt-sc7280
+              - qcom,apss-wdt-sdm845
+              - qcom,apss-wdt-sdx55
+              - qcom,apss-wdt-sm6350
+              - qcom,apss-wdt-sm8150
+              - qcom,apss-wdt-sm8250
+          - const: qcom,kpss-wdt
+      - items:
+          - enum:
+              - qcom,kpss-wdt
+              - qcom,kpss-timer
+              - qcom,kpss-wdt-apq8064
+              - qcom,kpss-wdt-ipq4019
+              - qcom,kpss-wdt-ipq8064
+              - qcom,kpss-wdt-msm8960
+              - qcom,scss-timer
 
   reg:
     maxItems: 1