drm/amd/display: Disable mem low power for CM HW block on DCN3.1

[WHY]
Currently causes visible flicker in some scenarios on OLED eDPs

Reviewed-by: Haonan Wang <haonan.wang2@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Michael Strauss <michael.strauss@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>