A 15-year-old kid was found shot to death in the north Bronx yesterday at 5:55 p.m., cops say. Phillip Johnson, of 728 East 221st Street, was discovered at the corner of East 219th Street and White Plains Road. He had taken two bullets to the chest and was DOA at Jacobi Medical Center. Who did it? The NYPD notes, "Unknown suspects fled on foot in an unknown direction."