dt-bindings: remoteproc: qcom,glink-rpm-edge: drop redundant type from label

dtschema defines label as string, so $ref in other bindings is
redundant.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240226122854.86197-1-krzysztof.kozlowski@linaro.orgSigned-off-by: Bjorn Andersson <andersson@kernel.org>

Documentation/devicetree/bindings/remoteproc/qcom,glink-rpm-edge.yaml

@@ -18,7 +18,6 @@ properties:
     const: qcom,glink-rpm
 
   label:
-    $ref: /schemas/types.yaml#/definitions/string
     description:
       Name of the edge, used for debugging and identification purposes. The
       node name will be used if this is not present.