USA Network has reluctantly agreed to reschedule its telecast of “Fallen Champ: The Mike Tyson Story” 13 days after NBC airs the same special.Originally, USA wanted to air the Barbara Kopple-produced biography of the former boxing champion less than 24 hours after NBC’s telecast, but the Peacock network balked. NBC is airing the work on Feb. 12 and USA had it penciled in for Feb. 13 in prime time and then during the day on Feb. 14. According to a source familiar with the situation, NBC was asking for a 60 -day window, though after further discussion the two parties agreed on a 7- to 10-day window. USA could not schedule the project until Feb. 25. To do so the cabler will bump a repeat telecast of its Tuesday night boxing package. An afternoon telecast on Feb. 26 is also planned.