clk: qcom: videocc-sdm845: get rid of the test clock

The test clock isn't in the bindings and apparently it's not used by
anyone upstream.  Remove it.

Suggested-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20210405224743.590029-17-dmitry.baryshkov@linaro.org


Signed-off-by: Stephen Boyd <sboyd@kernel.org>