drm/ttm: remove cpu_address member from ttm_tt

Patch 3d50d4dcb0 exposed the CPU address of DMA-allocated pages as
returned by dma_alloc_coherent because Nouveau on Tegra needed it.

This is not required anymore - as there were no other users for it,
remove it and save some memory for everyone.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index bc5aa57..aee3c00 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -57,10 +57,8 @@
 {
 	ttm->ttm.pages = drm_calloc_large(ttm->ttm.num_pages,
 					  sizeof(*ttm->ttm.pages) +
-					  sizeof(*ttm->dma_address) +
-					  sizeof(*ttm->cpu_address));
-	ttm->cpu_address = (void *) (ttm->ttm.pages + ttm->ttm.num_pages);
-	ttm->dma_address = (void *) (ttm->cpu_address + ttm->ttm.num_pages);
+					  sizeof(*ttm->dma_address));
+	ttm->dma_address = (void *) (ttm->ttm.pages + ttm->ttm.num_pages);
 }
 
 #ifdef CONFIG_X86
@@ -244,7 +242,6 @@
 
 	drm_free_large(ttm->pages);
 	ttm->pages = NULL;
-	ttm_dma->cpu_address = NULL;
 	ttm_dma->dma_address = NULL;
 }
 EXPORT_SYMBOL(ttm_dma_tt_fini);