Revert "drm/amdgpu: add pipeline sync while vmid switch in same ctx"

This reverts commit 2ba272d7bde27e1db2cf1c6cee49b01b7ea08989.

The issue fixed by this patch is specific to compute rings and the
previous patch was enough.  Additionally, this patch as been traced
to strange behavior on some CZ systems so we might as well drop it.
3 files changed