Fried Cornmeal Shrimp with Butternut Squash Risotto

1 1 3/4- to 2-pound butternut squash 24 uncooked large shrimp (about 1 1/4 pounds), peeled, deveined 3 1/2 tablespoons extra-virgin olive oil, divided 3 large garlic cloves, peeled, smashed, plus 2 large garlic cloves, chopped 1 cup cornmeal 1/2 teaspoon salt 1/2 teaspoon freshly ground black pepper 5 cups low-salt chicken broth 1 1/2 cups chopped onion 4 teaspoons finely chopped fresh thyme, divided 1 1/2 cups arborio rice or medium-grain white rice 1/2 cup dry white wine Vegetable oil (for frying) 1/2 cup freshly grated Parmesan cheese