drm/amd/powerplay: translate power_profile mode to pplib workload type

Correctly translate the power profile specified by user to workload
type accepted by SMU fw.

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