Apple plans to start offering an online TV service with about 25 channels this fall, The Wall Street Journal reports. The slimmed-down TV bundle, anchored by networks ABC, CBS and Fox and featuring popular cable channels like ESPN and FX, would be available on all devices powered by Apple’s iOS operating system, including iPhones and iPads, as well as Apple TV set-top boxes. People familiar with the talks said NBC and its family of cable networks…