Trusted Services TEE driver v2

Refactor the driver to use the new Trusted Services RPC ABI. Remove the
capabilty of handling multiple RPC ABIs based on SP UUID, the scope of
the driver is Trusted Services only so this feature is not needed.
Change the user space interface to get aligned with the requirements of
the new RPC mechanism.

Signed-off-by: Balint Dobszay <balint.dobszay@arm.com>
Change-Id: I29d4d4a2790568b85e8f2d5f1f631f1dc2c73acb