The only iommu function call in this driver is a
tegra_dev_iommu_get_stream_id() which does not allocate anything and does
not take any reference.

So there is no point in calling iommu_fwspec_free() in the remove function.

Remove this incorrect function call.

Fixes: 0880bb3b ("crypto: tegra - Add Tegra Security Engine driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Tested-by: Akhil R <akhilrajeev@nvidia.com>
Acked-by: Akhil R <akhilrajeev@nvidia.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>