| I'm pretty sure that there aren't any D-tuners made by Yamaha itself, but you could probably get a D-tuner from Hipshot that would fit your Yamaha. Just take out a tuner, measure the diameter of the hole and compare the measurement to the specs of one of Hipshots D-tuner on their website.
If the Hipshot D-tuner is a little too big for the hole in your Yamaha's peghead, it is fairly simple to either ream the hole bigger yourself (I'd recommend buying a nice peghead reamer for that job) or taking it to a luthier so they can ream the hole larger...
If the hole in your Yamaha's peghead is bigger than the D-tuner, you could plug the hole and re-drill it, but this is more complicated and you may want a luthier to do the operation. | 
