cpu_map: Fix SierraForest CPU model

cpu_map: Fix SierraForest CPU model

The model was defined with two CPU features that cannot be explicitly
configured in QEMU (it knows the MSR bits, but there's no name
associated with them). The features should have never existed in the CPU
map. While removing them from the list of features and existing CPU
models is not trivial (to avoid compatibility issues), we can at least
fix the SierraForest CPU model added in this release cycle.

The rest will be handled later in a separate series.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>