drm: revert "expand replace_fence to support timeline point v2"

This reverts commit 9a09a423.

The whole interface isn't thought through. Since this function can't
fail we actually can't allocate an object to store the sync point.

Sorry, I should have taken the lead on this from the very beginning and
reviewed it more thoughtfully. Going to propose a new interface as a
follow up change.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Link: https://patchwork.freedesktop.org/patch/265580/