drm/msm/disp/dpu1: add support for dspp sub block flush in sc7280

drm/msm/disp/dpu1: add support for dspp sub block flush in sc7280

Flush mechanism for DSPP blocks has changed in sc7280 family, it
allows individual sub blocks to be flushed in coordination with
master flush control.

Representation: master_flush && (PCC_flush | IGC_flush .. etc )

This change adds necessary support for the above design.

Changes in v1:
- Few nits (Doug, Dmitry)
- Restrict sub-block flush programming to dpu_hw_ctl file (Dmitry)

Changes in v2:
- Move the address offset to flush macro (Dmitry)
- Separate ops for the sub block flush (Dmitry)

Changes in v3:
- Reuse the DPU_DSPP_xx enum instead of a new one (Dmitry)

Changes in v4:
- Use shorter version for unsigned int (Stephen)

Changes in v5:
- Spurious patch please ignore.

Changes in v6:
- Add SOB tag (Doug, Dmitry)

Changes in v7:
- Cache flush mask per dspp (Dmitry)
- Few nits (Marijn)

Changes in v8:
- Few nits (Marijn)

Changes in v9:
- Use DSPP enum while accessing flush mask to make it readable (Dmitry)
- Few nits (Dmitry)

Changes in v10:
- Fix white spaces in a separate patch (Dmitry)

Changes in v11:
- Define a macro for dspp flush selection (Marijn)
- Few nits (Marijn)

Changes in v12:
- Minor comments (reorder macros and a condition) (Marijn)

Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
Tested-by: Douglas Anderson <dianders@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/520701/
Link: https://lore.kernel.org/r/1674814487-2112-1-git-send-email-quic_kalyant@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>