dt-bindings: pinctrl: qcom,sc8180x: drop ref to pinctrl.yaml

The binding references common Qualcomm TLMM pin controller schema, which
references pinctrl.yaml.
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20221017230012.47878-3-krzysztof.kozlowski@linaro.orgSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Documentation/devicetree/bindings/pinctrl/qcom,sc8180x-pinctrl.yaml

@@ -14,7 +14,6 @@ description: |
   SC8180X platform.
 
 allOf:
-  - $ref: "pinctrl.yaml#"
   - $ref: /schemas/pinctrl/qcom,tlmm-common.yaml#
 
 properties: