OAKLAND, Calif. — Kyle Bradish had eight strikeouts in six dominant innings, Jorge Mateo hit an inside-the-park home run and the Baltimore Orioles beat the last-place Oakland Athletics 12-1 on Sunday to complete a three-game sweep. Ryan Mountcastle extended his on-base streak to a career-high 26 games with three hits including his 17th home run to pace the Orioles’ 17-hit …