SAN DIEGO — MacKenzie Gore’s path from top prospect to the mound on Friday for his MLB debut has been anything but typical. Figuratively and literally. He’d already made one superb start in Round Rock for Triple-A El Paso, flown back to Peoria, Ariz., to fetch his car and was two hours out from Southwest University Park when his phone rang. A.J. Preller was on the line with a question. “Do you want to throw your bullpen in El Paso or San Francisco?” Yep. Gore had gotten the call. Finally. “It’s definitely a little sweeter,” the 23-year-old left-hander said in front of his locker at Petco Park,…