drm/amd/powerplay: add set/get_power_profile_mode for Raven (v2)

The power profile allows the user to adjust the power state
heuristics for clock level transitions.

v2: squash in warning fix (Alex)

Reviewed-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Chengming Gui <Jack.Gui@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>