Stipe Miocic's Serious About Boxing Fury & Joshua, Wants No Smoke W/ Mike Tyson

Stipe Miocic wants to box Anthony Joshua or Tyson Fury, but not even the greatest UFC heavyweight of all-time is willing to step in the ring with Mike Tyson ... despite Iron Mike being 54 years old. 38-year-old Miocic tells TMZ Sports he's…