Revert "drm/amd/display: correct hostvm flag"

This reverts commit 796d6a37.

4K144 resolution isn't available on DCN31.

Reviewed-by: Sherry Wang <Yao.Wang1@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>