Revert "drm/amdgpu: remove fence fallback"

This reverts commit 9b0df0937a852d299fbe42a5939c9a8a4cc83c55.
This commit breaks KCQ IB test and S3 on Polaris 11.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
3 files changed