MCE, AMD: Remove functional unit references

Having the functional unit names in each bank decode is only misleading
as this code supports multiple families and there's no guarantee the
mapping between FUs and MCE banks will stay the same.

And also, knowing the functional unit name doesn't help much since you
end up looking at the respective BKDG anyway.

So drop all FU references and use the MC bank numbers instead.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>