drm/amdgpu: Fix vce work queue was not cancelled when suspend

commit 61ea6f5831974ebd1a57baffd7cc30600a2e26fc upstream.

The vce cancel_delayed_work_sync never be called.
driver call the function in error path.

This caused the A+A suspend hang when runtime pm enebled.
As we will visit the smu in the idle queue. this will cause
smu hang because the dgpu has been suspend, and the dgpu also
will be waked up. As the smu has been hang, so the dgpu resume
will failed.

Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>