SAN FRANCISCO — One of the top hitting prospects in baseball joined the league’s worst offense Monday when the Giants called up 21-year-old first baseman Bryce Eldridge. “He likes what he’s walking into,” Tony Vitello, manager of the 13-21 squad, said. “I’ll say that.” The Giants are hoping top prospect Bryce Eldridge can provide a spark in what’s been an anemic offense. Jayne Kamin-Oncea-Imagn Images The Giants rank last in the league in runs scored. They plated nine over the course of their most recent road trip while losing all six games. They rank last in walks and home runs, too. This is no soft landing: They’re counting on the 6-foot-7 slugger to help turn things around. In that case, some good news: “I’m feeling sexy at the plate right now,” Eldridge said with a grin to a horde of more than a dozen reporters and cameras in front of his locker, where a No. 8 jersey hung.…