drm/radeon/kms: free ib pool on module unloading

ib pool weren't free for various newer asic on module unload.
This doesn't cause much arm but still could be candidate for
stable.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
cc: stable@kernel.org
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/rv770.c b/drivers/gpu/drm/radeon/rv770.c
index 8bb347d..4de5189 100644
--- a/drivers/gpu/drm/radeon/rv770.c
+++ b/drivers/gpu/drm/radeon/rv770.c
@@ -1368,6 +1368,7 @@
 	r700_cp_fini(rdev);
 	r600_irq_fini(rdev);
 	radeon_wb_fini(rdev);
+	radeon_ib_pool_fini(rdev);
 	radeon_irq_kms_fini(rdev);
 	rv770_pcie_gart_fini(rdev);
 	rv770_vram_scratch_fini(rdev);