clk: qcom: cpu-8996: skip ACD init if the setup is valid

Check whether L2 registers contain correct values and skip programming
if they are valid. This follows the code present downstream.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230113120544.59320-7-dmitry.baryshkov@linaro.org