Widebus feature will transmit two pixel data per pixel clock to interface.
Timing engine provides driving force for this purpose. This patch base
on HPG (Hardware Programming Guide) to revise timing engine register
setting to accommodate both widebus and non widebus application. Also
horizontal width parameters need to be reduced by half since two pixel
data are clocked out per pixel clock when widebus feature enabled.

Widebus can be enabled individually at DP. However at DSI, widebus have
to be enabled along with DSC to achieve pixel clock rate be scaled down
with same ratio as compression ratio when 10 bits per source component.
Therefore this patch add no supports of DSI related widebus and compression.

Changes in v2:
-- remove compression related code from timing
-- remove op_info from  struct msm_drm_private
-- remove unnecessary wide_bus_en variables
-- pass wide_bus_en into timing configuration by struct msm_dp

Changes in v3:
-- split patch into 3 patches

Changes in v4:
-- rework timing engine to not interfere with dsi/hdmi
-- cover both widebus and compression

Changes in v5:
-- remove supports of DSI widebus and compression

Changes in v7:
-- split this patch into 3 patches
-- add Tested-by

Changes in v8:
-- move new registers writes under DATA_HCTL_EN features check.

Changes in v10:
-- add const inside dpu_encoder_is_widebus_enabled()
-- drop useless parenthesis please
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/476281/
Link: https://lore.kernel.org/r/1645824192-29670-4-git-send-email-quic_khsieh@quicinc.comSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>