Latin America’s booming clean energy market is attracting the world’s energy giants, which are driving down prices and squeezing out the little guys. Smaller developers were instrumental in taking wind and solar mainstream in the region, making headlines in recent years by offering record low prices at government auctions. Now they’re getting undercut by bigger rivals like Enel SpA, AES Corp. and Iberdrola SA. The emergence of international power companies in Latin America is a testament to how mature…