drm/msm: move MAX_H_TILES_PER_DISPLAY to the DPU driver

The MAX_H_TILES_PER_DISPLAY const is only used by the DPU driver, move
it to the corresponding header.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/622536/
Link: https://lore.kernel.org/r/20241031-dpu-move-topology-v1-2-8ffa8122d3b6@linaro.org