Charles Krupa/AP As the Patriots prepare to open training camp, a trio of players will begin their summer work on the sidelines. According to ESPN’s Mike Reiss, EDGE Harold Landry III and tight end C.J. Dippre have been placed on the active/physically unable to perform (PUP) list, while running back Terrell Jennings is opening camp on the active/non-football injury (NFI) list. These designations mean that while all three players count…