Whole berries in a mixture like cheesecake will usually never turn out right.
Even if the berries are dried of their moisture, they can still separate from the batter while baking and could make the whole thing unstable.
If you want to put berries in the mixture, I would suggest slightly dried out berries. Fully dried out berries will just become gummy, as there isn't enough moisture in the batter for them to pull out while baking, in order to plump up. If you use half dried berries, where half of the moisture is dried out of the berry, they should pull enough moisture from the batter while baking to make them plump enough to have berries show up in the cake.
Another trick is using fresh berries, drying them off of all external moisture, and dipping them in white chocolate.
Once they have dried, you will have "berry bombs" you can put in your mixture. I would suggest pouring a bit of batter, then place your berry bombs on top of that layer by hand, then pour another layer of batter, then hand place more berry bombs, then cover with remaining batter. Mixing them in can break the chocolate shell on the berry and cause seepage while baking. This way, the berry stays in tact while baking, doesn't loose moisture into the cake and the white chocolate merges with the batter so the berry doesn't make a gap in the cake. But again, there are no guarantees.
Your best bet would be to use berry jam or jelly and swirl it into the batter before baking, and then top with fresh glazed or sugared berries. Or you could just go with using fully dried berries in the cake, but again, you might get gummy berries that way.
Hope that helps.