Add documentation of OSSL_CRMF_CERTID_dup()

Fixes #12190

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/12208)

doc/man3/X509_dup.pod

@@ -139,6 +139,7 @@ OSSL_CMP_PKISI_free,
 OSSL_CMP_PKISI_it,
 OSSL_CMP_PKISI_new,
 OSSL_CMP_PKISTATUS_it,
+OSSL_CRMF_CERTID_dup,
 OSSL_CRMF_CERTID_free,
 OSSL_CRMF_CERTID_it,
 OSSL_CRMF_CERTID_new,