radv, ac/nir: Fix regression with tessellation.
We recently made some effort to reduce the LDS use of TCS: The lowering no longer uses the same output location mapping when storing TCS outputs to LDS and VRAM. This means that the same patch will use a different amount of LDS and VRAM.
Therefore, we need to properly calculate the patch size in VRAM when determining the number of output patches.
Other than that, there is also a minor fix for the lowering, but that didn't cause any issues in practice.