BERLIN — Ford will stop building the Fiesta small car in Cologne, Germany, by next summer, a year earlier than planned, marking the end of a famed nameplate that first appeared in 1976. When Fiesta output ends, production of Ford’s new Volkswagen-based all-electric crossover will begin, also a year earlier than planned. The Fiesta has been one of Ford’s most popular vehicles, but sales have declined as European consumers switch from hatchbacks to crossovers such as the Ford Puma. The automaker ended production of the three-door Fiesta last summer amid falling sales.