Add revstat into optdata of Cred according to OCF spec

Add revstat into optdata of Cred according to OCF spec

Accoding to ocf security spec, revstat is mandatory property.
"revstat": {
  "type": "boolean",
  "description": "Revocation status flag
                - true = revoked, false = not revoked"

Patch 1: upload patch.
Patch 2: update json2cbor.c to convert revstat

Change-Id: Ifbb7743f8321cb8afbf69cfa307694598e24ea6e
Signed-off-by: js126.lee <js126.lee@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/15951
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Chul Lee <chuls.lee@samsung.com>
Reviewed-by: Randeep Singh <randeep.s@samsung.com>
(cherry picked from commit 514ef82fb2ec9865a792b5f252ffbaeed3a3e7eb)
Reviewed-on: https://gerrit.iotivity.org/gerrit/16035