Place chicken in a 1-1/2-qt. slow cooker; sprinkle with chili powder and lime juice. Cook, covered, on low 3-4 hours or until tender., Remove chicken; discard cooking juices. Shred chicken with 2 forks; return to slow cooker. Add corn and salsa; cook, covered, on low about 30 minutes or until heated through, stirring occasionally., Transfer to a large bowl; stir in cheese, pepper and green onions. Sprinkle with cilantro; serve with tortilla scoops.