The type of port identifier encoding used to identify the port
component associated with the local port.
When port id subtype is configured as portcomp/local it is mandatory
to configure the fsLldpLocPortId object. If fsLldpLocPortId
object is not configured then current value of fsLldpLocPortId is
advertised.
When chassis id subtype is configured as ifalias/macaddr/nwaddr/
ifname/agentcircuitid it is not required to configure fsLldpLocPortId
object. System specific values are used for setting fsLldpLocPortId
object.