By TOM SHANAHAN Bill Walton’s mind cheerfully hums songs illuminating life’s complexities, but he burst out with renewed hope last spring and summer. The chord struck was college athletes outspokenly supporting Black Lives Matter protests. “I’m all for it,” Walton said. “It’s fantastic -- a dream come true. It’s what I grew up hoping the future would be; now it’s here.” What Bob Dylan song might Walton be singing to himself? Maybe, “Blowin’ in the Wind.” How about…