Revert "drm/amd/display: Enable CM low mem power optimization"

This reverts commit fcfc6cee.

[why]
Flickering observed. Regression search pointed to this being
the offending commit.

Reviewed-by: Charlene Liu <charlene.liu@amd.com>
Reviewed-by: Yihan Zhu <yihan.zhu@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Gabe Teeger <gabe.teeger@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>