The magsafe cable/port you're talking about exists, and is on the current line of MacBook Pros. However, the magsafe feature on iPhones is something completely

The magsafe cable/port you're talking about exists, and is on the current line of MacBook Pros. However, the magsafe feature on iPhones is something completely different, it's the system where they have magnets in the back of the phone which can be used to attach various accessories, attach the phone to mounts, or guide the phone to rest correctly on wireless charging pads.