Sister Wives star Janelle Brown’s son Garrison has passed away at age 25, RadarOnline.com has learned. Garrison is believed to have taken his own life. Garrison reportedly died of a self-inflicted gunshot wound on Tuesday in Flagstaff, Arizona, where he had been residing since moving away from his mother and father, Kody Brown. According to the Flagstaff Police Department, officers were dispatched to Garrison’s home on a report of a death. Garrison’s brother Gabriel is believed to have arrived at the home and discovered his body. No foul play has been suspected at this time. This is a developi…