drm/msm/dpu: support setting up two independent DSI connectors

drm/msm/dpu: support setting up two independent DSI connectors

Move setting up encoders from set_encoder_mode to
_dpu_kms_initialize_dsi() / _dpu_kms_initialize_displayport(). This
allows us to support not only "single DSI" and "bonded DSI" but also "two
independent DSI" configurations. In future this would also help adding
support for multiple DP connectors.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Link: https://lore.kernel.org/r/20210717124016.316020-4-dmitry.baryshkov@linaro.org
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>