Toshiba has chosen a group led by Bain Capital — which includes Apple — to buy its ailing chip business, The Wall Street Journal reports. Toshiba has outlined a plan to stay involved in the business after the estimated $18 billion sale, signing a “nonbinding document saying they intended to reach a deal by September 30.” The deal still has to clear a review from antitrust regulators and objections from Toshiba partner Western Digital,…