dt-bindings: remoteproc: qcom,glink-edge: add GPR node

The existing SM8450 DTS (and newer platforms) come with a "gpr" child node,
not "apr":

  sm8450-sony-xperia-nagara-pdx224.dtb: remoteproc@30000000: glink-edge: Unevaluated properties are not allowed ('gpr' was unexpected)
    From schema: Documentation/devicetree/bindings/remoteproc/qcom,sm8350-pas.yaml

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221223132213.81273-1-krzysztof.kozlowski@linaro.org