bhyve.8: Make synopsis more readable

There is no need to squeeze all the possible options into one synopsis
entry. Let "-l help" and "-s help" be listed separately.

While here, keep -s and its arguments on the same line.

MFC after:	2 weeks

usr.sbin/bhyve/bhyve.8

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 18, 2021
+.Dd April 18, 2021
 .Dt BHYVE 8
 .Os
 .Sh NAME
@@ -49,7 +49,7 @@
 .Op Fl k Ar file
 .Oo Fl l
 .Sm off
-.Cm help | Ar lpcdev Op Cm \&, Ar conf
+.Ar lpcdev Op Cm \&, Ar conf
 .Sm on
 .Oc
 .Oo Fl m
@@ -63,13 +63,17 @@
 .Op Fl o Ar var Ns Cm = Ns Ar value
 .Op Fl p Ar vcpu Ns Cm \&: Ns Ar hostcpu
 .Op Fl r Ar file
-.Oo Fl s
 .Sm off
-.Cm help | Ar slot Cm \&, Ar emulation Op Cm \&, Ar conf
+.Oo Fl s\~
+.Ar slot Cm \&, Ar emulation Op Cm \&, Ar conf
 .Sm on
 .Oc
 .Op Fl U Ar uuid
 .Ar vmname
+.Nm
+.Fl l Cm help
+.Nm
+.Fl s Cm help
 .Sh DESCRIPTION
 .Nm
 is a hypervisor that runs guest operating systems inside a