MMHUB v4.1.0 only support fixed cache mode, so
only use legacy invalidation accordingly.
Signed-off-by: Likun Gao <Likun.Gao@amd.com>
Reviewed-by: Frank Min <Frank.Min@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 9192c761)