drm/msm/mdp5: migrate SMP dumping to using atomic_print_state

drm/msm/mdp5: migrate SMP dumping to using atomic_print_state

The Shared Memory Pool (SMP) state is a part of the MDP5's private
object state. Use existing infrastructure, atomic_print_state()
callback, to dump SMP state (which also makes it included into
debugfs/dri/N/state). This allows us to drop the custom debugfs file
too.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/570179/
Link: https://lore.kernel.org/r/20231203000532.1290480-5-dmitry.baryshkov@linaro.org