clk: qcom: Use ARRAY_SIZE in videocc-sc7180 for parent clocks

It's nicer to use ARRAY_SIZE instead of hardcoding.  Had we always
been doing this it would have prevented a previous bug.  See commit
74c31ff9

 ("clk: qcom: gpu_cc_gmu_clk_src has 5 parents, not 6").

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lkml.kernel.org/r/20200203103049.v4.13.If37e4b1b5553ac9db5ea51e84a6eec286cdf209e@changeid


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