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/r600.c b/drivers/gpu/drm/radeon/r600.c
index f79d2cc..bc54b26 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -2628,6 +2628,7 @@
 	r600_cp_fini(rdev);
 	r600_irq_fini(rdev);
 	radeon_wb_fini(rdev);
+	radeon_ib_pool_fini(rdev);
 	radeon_irq_kms_fini(rdev);
 	r600_pcie_gart_fini(rdev);
 	radeon_agp_fini(rdev);