drm/amdgpu: Let KFD sync with VM fences

Change the rules for amdgpu_sync_resv to let KFD synchronize with VM
fences on page table reservations. This fixes intermittent memory
corruption after evictions when using amdgpu_vm_handle_moved to update
page tables for VM mappings managed through render nodes.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>