drm/msm/dpu: Drop useless comments

drm/msm/dpu: Drop useless comments

Drop comments about SoC before each 'struct dpu_lm_sub_blks' for given
SoC because it's duplicating the actual name of structure.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/651251/
Link: https://lore.kernel.org/r/20250430-b4-sm8750-display-v5-11-8cab30c3e4df@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>