COOK bacon and onions in Dutch oven or large deep skillet on medium heat 3 to 4 min. or until onions are crisp-tender, stirring occasionally. Add broth, potatoes and corn; stir. Bring to boil; simmer on medium-low heat 15 min. or until potatoes are tender.
MIX mayo and flour in medium bowl with whisk until blended. Gradually stir in milk. Add to ingredients in Dutch oven along with the turkey; cook on medium heat 5 min. or until heated through and slightly thickened, stirring constantly. Remove from heat; stir in spinach.
SERVE topped with cheese.