By Richa Naidu LONDON (Reuters) – Top baby formula makers Reckitt Benckiser and Nestle have ramped up supplies to the United States to resolve a shortage that has emptied shelves and caused panic among parents. Baby formula aisles at U.S. supermarkets have been decimated since top U.S. manufacturer Abbott Laboratories in February recalled formulas after complaints of bacterial infections. Abbott said on Monday it had reached an agreement with the U.S. health regulator to resume production of baby formula at its Michigan plant, marking a major step towards resolving the nationwide shortage. In …