iommu/arm-smmu: Fix memory leak with respect to TBU data structures

When the TBU devices unbind from the TBU driver, all of the
resources acquired through the devm_* functions are released.
However, the interconnect resources are not acquired through the
devm_* APIs.

Since the TBU driver does not have a remove() call to release the
interconnect resources, this results in a memory leak. Fix this by
adding a remove() call to release the interconnect resources on
device and driver unbind.

Change-Id: Iac6b5a6b1da7ff989ae36775b39c5fa61294270a
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>