LLDP is enabled by default on ProCurve switches, but you haven't said what model(s) you have.
Perhaps something like this (from 5400zl) is what you are after?
switch01(config)# lldp config b5 medTlvEnable ?
capabilities Capability TLV
network_policy Network Policy TLV
location_id Location Id TLV
poe Poe TLV