drm/nouveau/mmu: fix vram heap sizing

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvkm/subdev/mmu/base.c

@@ -316,9 +316,9 @@ nvkm_mmu_vram(struct nvkm_mmu *mmu)
 {
 	struct nvkm_device *device = mmu->subdev.device;
 	struct nvkm_mm *mm = &device->fb->ram->vram;
-	const u32 sizeN = nvkm_mm_heap_size(mm, NVKM_RAM_MM_NORMAL);
-	const u32 sizeU = nvkm_mm_heap_size(mm, NVKM_RAM_MM_NOMAP);
-	const u32 sizeM = nvkm_mm_heap_size(mm, NVKM_RAM_MM_MIXED);
+	const u64 sizeN = nvkm_mm_heap_size(mm, NVKM_RAM_MM_NORMAL);
+	const u64 sizeU = nvkm_mm_heap_size(mm, NVKM_RAM_MM_NOMAP);
+	const u64 sizeM = nvkm_mm_heap_size(mm, NVKM_RAM_MM_MIXED);
 	u8 type = NVKM_MEM_KIND * !!mmu->func->kind;
 	u8 heap = NVKM_MEM_VRAM;
 	int heapM, heapN, heapU;