Pats add CB Chimdi Chekwa

Darrelle Revis is gone, and Brandon Browner may be close behind him.  So the Patriots need cornerbacks. They’ve added one via free agency.  Per a league source, former Raiders cornerback Chimdi Chekwa has signed a one-year contract with New England. A fourth-round pick in 2011 from Ohio State, Chekwa appeared in 10 games with two…