drm/tegra: Use lockless gem BO free callback

No dev->struct_mutex anywhere to be seen.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Terje Bergström <tbergstrom@nvidia.com>
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-28-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/tegra/drm.c

@@ -932,7 +932,7 @@ static struct drm_driver tegra_drm_driver = {
 	.debugfs_cleanup = tegra_debugfs_cleanup,
 #endif
 
-	.gem_free_object = tegra_bo_free_object,
+	.gem_free_object_unlocked = tegra_bo_free_object,
 	.gem_vm_ops = &tegra_bo_vm_ops,
 
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,