By Matt Hladik After letting J.C. Jackson walk, the New England Patriots have a major need at cornerback heading into this month’s NFL Draft. ESPN’s Mel Kiper Jr. proposed an interesting way they might fill it in a conversation with colleague Mike Reiss. In Reiss’ column, published this morning, he quotes Kiper as saying Cincinnati’s Sauce Gardner, LSU’s Derek Stingley Jr. and Washington’s Trent McDuffie are the clear-cut top cornerbacks in this year’s draft. With the likelihood of one of them falling to No. 21, New England’s selection, seemingly slim, Kiper said he wouldn’t be surprised if Bi…