drm/msm: move msm_display_topology to the DPU driver

The struct msm_display_topology is only used by the DPU driver. Remove
it from the global header and move it to DPU-specific header.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/622534/
Link: https://lore.kernel.org/r/20241031-dpu-move-topology-v1-1-8ffa8122d3b6@linaro.org