drm/amd/powerplay: add function get_workload_type_map for swsmu

1.add new callback function get_workload_byte for smu
2.remove old workload map function

Signed-off-by: Kevin Wang <kevin1.wang@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>