Provide atomic_print_state callback to the DPU's private object. This
way the debugfs/dri/0/state will also include RM's internal state.

Example output (RB5 board, HDMI and writeback encoder enabled)

resource mapping:
	pingpong=31 36 # # # # - - - - -
	mixer=31 36 # # # # -
	ctl=# # 31 36 # #
	dspp=# # # #
	dsc=# # # # - -
	cdm=#
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/579648/
Link: https://lore.kernel.org/r/20240222-fd-rm-state-v5-1-4a6c81e87f63@linaro.org