API reference: update dnszone_add generated doc
Update doc/api/dnszone_add.md after commit c74c701
(Set 'idnssoaserial' to deprecated)
Related: https://pagure.io/freeipa/issue/9249
Signed-off-by: Florence Blanc-Renaud <flo@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>