By Chris JenneweinTimes of San Diego Chris Jennewein SAN DIEGO — A poll released Friday by UC Berkeley’s Institute of Governmental Studies finds Democrat Adam Schiff and Republican Steve Garvey in a statistical dead heat for Senate as the March 5 primary nears. Garvey, a retired baseball star, was the choice of 27% of likely voters polled, with Schiff, a 12-term congressman, second at 25%. Democratic Congress members Katie Porter and Barbara Lee were third and fourth at 19% and 8%. Mark DiCamillo, director of the poll, said support for Garvey has grown significantly in recent weeks. “A big par…