drm/amd/powerplay: update current profile mode only when it's really applied

No need to update current profile mode if the new profile mode
does not take effect in fact.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>