drm/msm/dsi: dsi_cfg: Deduplicate identical structs

drm/msm/dsi: dsi_cfg: Deduplicate identical structs

Some structs were defined multiple times for no apparent reason.
Deduplicate them.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/527653/
Link: https://lore.kernel.org/r/20230307-topic-dsi_qcm-v6-4-70e13b1214fa@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>