Add Synology Hardware/Version/Serial detection (#8087)

* Add Synology Hardware/Version/Serial detection

Fixes #7957

* Add DSM test data for hardware/version/serial

* updated to use snmp_get_multi_oid and save more test data

* added json data

* re-saved json data for dsm

* Update dsm.json

* Update dsm_ds916.json

* Update dsm_ds214.json

includes/polling/os/dsm.inc.php

@@ -0,0 +1,30 @@
+<?php
+/**
+ * dsm.inc.php
+ *
+ * -Description-
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @package    LibreNMS
+ * @link       http://librenms.org
+ * @copyright  2018 Nick Peelman
+ * @author     Nick Peelman <nick@peelman.us>
+ */
+
+$tmp_dsm  = snmp_get_multi_oid($device, 'modelName.0 version.0 serialNumber.0', '-OUQs', 'SYNOLOGY-SYSTEM-MIB');
+$hardware = $tmp_dsm['modelName.0'];
+$version  = $tmp_dsm['version.0'];
+$serial   = $tmp_dsm['serialNumber.0'];
+unset($tmp_dsm);