drm/msm/dpu: expand .clk_ctrls definitions

Use more standard initialisation for .clk_ctrls definitions. Define a
single .clk_ctrls field and use array init inside.

Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Tested-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/545368/
Link: https://lore.kernel.org/r/20230704022136.130522-7-dmitry.baryshkov@linaro.org