Obsolete reference to RFC3272

[italobusi]

From I-D nits:

  -- Obsolete informational reference (is this intentional?): RFC 3272
     (Obsoleted by RFC 9522)

Shall we update the references?

Note that the references in YANG are specifying the section numbers of RFC 3272

[italobusi]

2024-02-02 TE Call

Update the reference to RFC 9522 and check the section numbers