Preamble in linux doesn't mean it is CE PREAMBLE IB,
instead it means this IB could be dropped if no
ctx switch happens.
Signed-off-by: NMonk Liu <Monk.Liu@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>