Add support for Huawei S6720

[jordani0]

Hello Team,
Would it be possible to add mentioned switch?

snmpget -c xxxxxxx -On -v 2c xxxxxxxx .1.3.6.1.2.1.1.1.0

.1.3.6.1.2.1.1.1.0 = STRING: "S6720-30C-EI-24S-AC
Huawei Versatile Routing Platform Software
VRP (R) software,Version 5.160 (S6720 V200R009C00SPC500)
Copyright (C) 2007 Huawei Technologies Co., Ltd."

snmpget -c xxxxx -On -v 2c xxxxxxx .1.3.6.1.2.1.1.2.0

.1.3.6.1.2.1.1.2.0 = OID: .1.3.6.1.4.1.2011.2.23.340

Thanks!