Cover ffarpc_call_ep with unit tests

Fully cover ffarpc_call_ep with unit tests to check proper error
handling of the component.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: Ibed2094f57285090f7160719fedb6e20c4505560
diff --git a/components/rpc/common/test/component.cmake b/components/rpc/common/test/component.cmake
new file mode 100644
index 0000000..0fed152
--- /dev/null
+++ b/components/rpc/common/test/component.cmake
@@ -0,0 +1,18 @@
+#-------------------------------------------------------------------------------
+# Copyright (c) 2022, Arm Limited and Contributors. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+#-------------------------------------------------------------------------------
+if (NOT DEFINED TGT)
+	message(FATAL_ERROR "mandatory parameter TGT is not defined.")
+endif()
+
+target_sources(${TGT} PRIVATE
+	"${CMAKE_CURRENT_LIST_DIR}/mock_rpc_interface.cpp"
+	)
+
+target_include_directories(${TGT} PRIVATE
+	"${CMAKE_CURRENT_LIST_DIR}"
+	)
+