virtual_oss.8 mention intel CPU tuning

Why do we have this in virtual_oss.8?
https://github.com/freebsd/virtual_oss/blob/main/virtual_oss.8#L329-L337

```
How to set intel based CPUs in performance mode:
.Bd -literal -offset indent
sysctl -aN | fgrep dev.hwpstate | fgrep epp | \
while read OID
do
sysctl ${OID}=0
done

sysctl kern.sched.preempt_thresh=224
```