drm/msm: less magic numbers in msm_mdss_enable

Replace magic register writes in msm_mdss_enable() with version that
contains less magic and more variable names that can be traced back to
the dpu_hw_catalog or the downstream dtsi files.

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/489578/
Link: https://lore.kernel.org/r/20220615135935.87381-1-dmitry.baryshkov@linaro.org


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>