Lots and Lots
The ESPN NFL site says there are 22. It lists all the NFL players by college. It shows their position and pro team.
The players who didn't go to college of players who when to a bad college.
Miami @ 42 players
NFL player Will Blackmon played for Boston College.
Playing now... 33http://espn.go.com/nfl/college/_/letter/n
NFL player Tre Boston played for North Carolina.