Add SNMP Cisco WS-C3750-48TS

Add SNMP Support for
Cisco WS-C3750-48TS: 48 RJ-45/10-100TX + 4 SFP/1000
Initial support Cisco 2851

Initial support for Cisco 2851.
Live CDP, Live LLDP, Live Ports not work.
NM and WIC cards not work.