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/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index e8a5ffb..a2d9008 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -3237,6 +3237,7 @@
 	r700_cp_fini(rdev);
 	r600_irq_fini(rdev);
 	radeon_wb_fini(rdev);
+	radeon_ib_pool_fini(rdev);
 	radeon_irq_kms_fini(rdev);
 	evergreen_pcie_gart_fini(rdev);
 	radeon_gem_fini(rdev);