tee: optee: Use UUID API for exporting the UUID

There is export_uuid() function which exports uuid_t to the u8 array.
Use it instead of open coding variant.

This allows to hide the uuid_t internals.
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

drivers/tee/optee/device.c

@@ -98,7 +98,7 @@ static int __optee_enumerate_devices(u32 func)
 		return -ENODEV;
 
 	/* Open session with device enumeration pseudo TA */
-	memcpy(sess_arg.uuid, pta_uuid.b, TEE_IOCTL_UUID_LEN);
+	export_uuid(sess_arg.uuid, &pta_uuid);
 	sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
 	sess_arg.num_params = 0;