PTP: Hybrid PTP and SyncE: LAG support

Junos OS supports Precision Time Protocol (PTP), Synchronous Ethernet, and hybrid mode over a link aggregation group (LAG). Link aggregation is a mechanism of combining multiple physical links into a single virtual link to achieve linear increase in bandwidth and to provide redundancy in case a link fails. The virtual link is referred to as an aggregated Ethernet interface or a LAG.