drm/radeon: track memory statistics about VRAM and GTT usage and buffer moves v2

The statistics are:
- VRAM usage in bytes
- GTT usage in bytes
- number of bytes moved by TTM

The last one is actually a counter, so you need to sample it before and after
command submission and take the difference.

This is useful for finding performance bottlenecks. Userspace queries are
also added.

v2: use atomic64_t

Signed-off-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_object.h b/drivers/gpu/drm/radeon/radeon_object.h
index 209b111..a9a8c11 100644
--- a/drivers/gpu/drm/radeon/radeon_object.h
+++ b/drivers/gpu/drm/radeon/radeon_object.h
@@ -151,7 +151,7 @@
 extern int radeon_bo_check_tiling(struct radeon_bo *bo, bool has_moved,
 				bool force_drop);
 extern void radeon_bo_move_notify(struct ttm_buffer_object *bo,
-					struct ttm_mem_reg *mem);
+				  struct ttm_mem_reg *new_mem);
 extern int radeon_bo_fault_reserve_notify(struct ttm_buffer_object *bo);
 extern int radeon_bo_get_surface_reg(struct radeon_bo *bo);