drm/msm/disp/dpu1: Add support for DSC in encoder

We need to configure the encoder for DSC configuration and calculate DSC
parameters for the given timing so this patch adds that support by
adding dpu_encoder_prep_dsc() which is invoked when DSC is enabled.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Patchwork: https://patchwork.freedesktop.org/patch/480920/
Link: https://lore.kernel.org/r/20220406094031.1027376-8-vkoul@kernel.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>