tee: add kernel internal client interface **not for mainline**

Adds a kernel internal TEE client interface to be used by other drivers.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
From: https://github.com/linaro-swg/linux.git
(cherry picked from commit 860c46087c99c24073cc722b12c0017bb0ce0a79)
2 files changed