SDID is hart-local only

Co-authored-by: Samuel Holland <[email protected]>
Signed-off-by: Ravi Sahita <[email protected]>

chapter3.adoc

@@ -10,9 +10,7 @@ associated with the supervisor domain. For most typical usages, the SDID will
 remain stable over the life of the supervisor domain. However, the SDID can be
 changed at the cost of fencing to flush any prior cached state. The SDID is
 unique only to a hart, hence, SDID must not be used to tag downstream
-transactions that are globally visible - implementations may map the SDID from
-the initiator to other (global) identifiers but that mapping is
-implementation-specific and out of scope of this specification.
+transactions that are globally visible.
 
 === Machine tracking table pointer (`mttp`)