arm64: dts: qcom: sm8250: Add GPU speedbin support

SM8250 has (at least) four GPU speed bins. With the support added on the
driver side, wire up bin detection in the DTS to restrict lower-quality
SKUs from running at frequencies they were not validated at.

Tested-by: Marijn Suijten <marijn.suijten@somainline.org> # On Sony Xperia 5 II (speed bin 0x7)
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230331-topic-konahana_speedbin-v3-5-2dede22dd7f7@linaro.org