dt-bindings: clock: qcom,mmcc-msm8998: drop core_bi_pll_test_se

The test clock apparently it's not used by anyone upstream. Remove it.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221228185237.3111988-6-dmitry.baryshkov@linaro.org