Add more accurate description of the pe parameter of function
amdgpu_vm_sdma_udpate and amdgpu_vm_cpu_update
Signed-off-by: NOak Zeng <Oak.Zeng@amd.com>
Reviewed-by: NChristian Konig <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>