dt-bindings: clock: qcom: Accept power-domains for GPUCC

In many designs the power-domains provided by the GPU clock controller
are powered by some GFX rail, add power-domains as a valid property to
allow this to be specified.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Acked-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230523010348.63043-1-quic_bjorande@quicinc.com