In medium bowl, combine all salsa ingredients; mix well. Let stand at room temperature for 15 to 30 minutes or refrigerate up to 2 hours to blend flavors. Stir before serving.
Spray broiler pan with nonstick cooking spray. In small bowl, combine chili powder, 1/2 teaspoon cumin, garlic salt and oregano; mix well. Lightly sprinkle both sides of salmon steaks with chili powder mixture; place on sprayed pan.
Broil 4 to 6 inches from heat for 8 to 12 minutes or until fish flakes easily with fork, turning once. Serve salsa with fish.