drm/amdgpu/smu13: update powersave optimizations

Only apply when compute profile is selected.  This is
the only supported configuration.  Selecting other
profiles can lead to performane degradations.

Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit d477e395)
Cc: stable@vger.kernel.org # 6.12.x