drm/amd/display: refactor pplib/smu communication

new per SoC interface instead legacy interface with lots of un-used
field that only cause confusion

model pp_smu like one of our HW objects with func_ptr interface
to call into it.  struct pp_smu as handle to call pp/smu

Signed-off-by: Tony Cheng <tony.cheng@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>