tee: optee: Add support for session login client UUID generation

Adds support for client UUID generation for OP-TEE. For group based session
logins membership is verified.

Signed-off-by: Vesa Jääskeläinen <vesa.jaaskelainen@vaisala.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>