drm/msm/dpu: add support for DSC encoder v1.2 engine

Add support for DSC 1.2 by providing the necessary hooks to program
the DPU DSC 1.2 encoder.

Changes in v3:
-- fixed kernel test rebot report that "__iomem *off" is declared but not
   used at dpu_hw_dsc_config_1_2()
-- unrolling thresh loops

Changes in v4:
-- delete DPU_DSC_HW_REV_1_1
-- delete off and used real register name directly

Changes in v7:
-- replace offset with sblk->enc.base
-- replace ss with slice

Changes in v8:
-- fixed checkpatch warning

Changes in v9:
-- replaced __dsc_calc_ob_max_addr() with __dsc_calc_output_buf_max_addr()
-- replaced variable num_ss with num_softslice
-- remove inline from function  declaration

changes in v10:
-- rewording text of changes in v9
-- replace DPU_DSC_NATIVE_422_EN with DPU_DSC_NATIVE_42x_EN
-- replace drm_dsc_calculate_flatness_det_thresh() with drm_dsc_flatness_det_thresh()

Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Patchwork: https://patchwork.freedesktop.org/patch/539500/
Link: https://lore.kernel.org/r/1685036458-22683-7-git-send-email-quic_khsieh@quicinc.com


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