arm_ffa: introduce sandbox test cases for UCLASS_FFA

Add functional test cases for the FF-A support

These tests rely on the FF-A sandbox emulator and FF-A
sandbox driver which help in inspecting the FF-A communication.

Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/test/dm/Makefile b/test/dm/Makefile
index 3799b1a..7ed0073 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0+
 #
 # Copyright (c) 2013 Google, Inc
-# Copyright 2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
+# Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
 
 obj-$(CONFIG_UT_DM) += test-dm.o
 
@@ -92,6 +92,7 @@
 obj-$(CONFIG_ACPI_PMC) += pmc.o
 obj-$(CONFIG_DM_PMIC) += pmic.o
 obj-$(CONFIG_DM_PWM) += pwm.o
+obj-$(CONFIG_ARM_FFA_TRANSPORT) += ffa.o
 obj-$(CONFIG_QFW) += qfw.o
 obj-$(CONFIG_RAM) += ram.o
 obj-y += regmap.o