tee: add OP-TEE driver

Adds a OP-TEE driver.

* Targets ARM and ARM64
* Supports using any U-Boot memory as shared memory
* Probes OP-TEE version using SMCs
* Uses OPTEE message protocol version 2 to communicate with secure world

Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Igor Opaniuk <igor.opaniuk@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
new file mode 100644
index 0000000..35adb83
--- /dev/null
+++ b/drivers/tee/optee/optee_private.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2018 Linaro Limited
+ */
+
+#ifndef __OPTEE_PRIVATE_H
+#define __OPTEE_PRIVATE_H
+
+void *optee_alloc_and_init_page_list(void *buf, ulong len, u64 *phys_buf_ptr);
+void optee_suppl_cmd(struct udevice *dev, void *shm, void **page_list);
+
+#endif /* __OPTEE_PRIVATE_H */