nvk: Allocate the correct VAB size on Kepler

We were allocating 128 KiB but claimed 256 KiB.  Allocate the right size
and assert that the size matches.

Fixes: 970bd70584 ("nvk: allocate VAB memory area")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35172>

src/nouveau/vulkan/nvk_cmd_draw.c

@@ -576,6 +576,7 @@ nvk_push_draw_state_init(struct nvk_queue *queue, struct nv_push *p)
       P_MTHD(p, NV9097, SET_VAB_MEMORY_AREA_A);
       P_NV9097_SET_VAB_MEMORY_AREA_A(p, vab_addr >> 32);
       P_NV9097_SET_VAB_MEMORY_AREA_B(p, vab_addr);
+      assert(dev->vab_memory->va->size_B == 256 * 1024);
       P_NV9097_SET_VAB_MEMORY_AREA_C(p, SIZE_BYTES_256K);
    }
 

src/nouveau/vulkan/nvk_device.c

@@ -243,7 +243,7 @@ nvk_CreateDevice(VkPhysicalDevice physicalDevice,
        pdev->info.cls_eng3d < MAXWELL_A) {
       /* max size is 256k */
       result = nvkmd_dev_alloc_mem(dev->nvkmd, &pdev->vk.base,
-                                   1 << 17, 1 << 20, NVKMD_MEM_LOCAL,
+                                   256 * 1024, 0, NVKMD_MEM_LOCAL,
                                    &dev->vab_memory);
       if (result != VK_SUCCESS)
          goto fail_slm;