drm/msm/dpu: move dpu_hw_pipe_cfg out of struct dpu_plane

struct dpu_hw_pipe_cfg represents an interim state during atomic
update/color fill, so move it out of struct dpu_plane.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Link: https://lore.kernel.org/r/20210930140002.308628-6-dmitry.baryshkov@linaro.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>