Apple suppliers are getting ready to manufacture a new iPad with a 12.9-inch screen by the first quarter of 2015, Bloomberg reports. Such a device has already been rumored for some time — previous reports claimed Apple was testing a larger iPad, with one late 2013 report claiming the company was testing five different 12.9-inch iPad prototypes for a release of two possible versions of such a device. Talk about the device has been quiet for some…