drm/amdgpu/swsmu: Only force workload setup on init

Needed to set the workload type at init time so that
we can apply the navi3x margin optimization.

Closes: drm/amd#3618
Link: drm/amd#3131


Fixes: c50fe289 ("drm/amdgpu/swsmu: always force a state reprogram on init")
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 580ad7cb)
Cc: stable@vger.kernel.org