added ref to normative MTT section from non-normative overview

Signed-off-by: Ravi Sahita <ravi@rivosinc.com>

intro.adoc

@@ -107,9 +107,10 @@ supervisor domain may be static (e.g. device assignment to a VM) or dynamic
 (e.g. scheduling a VM virtual cpu within a domain). The MTT for the supervisor
 domain active on the hart is programmed on the hart along with the supervisor
 domain identifier. The MTT does not perform any address translation; it simply
-provides access permissions for the physically addressed region/page (post any
-S-mode and/or G-stage address translation) to enforce the isolation properties
-per the use case requirements (see <<mtt-lookup>>).
+provides access permissions for the physically addressed regions/pages
+to enforce the isolation properties per the use case requirements (see
+<<mtt-lookup>> for a high-level illustration and section <<Smmtt>> for
+normative details).
 
 [caption="Figure {counter:image}: ", reftext="Figure {image}"]
 [title= "MTT lookup for Supervisor Domain Access", id=mtt-lookup]