Add mock for libsp/sp_discovery

Add mock_sp_discovery for mocking sp_discovery part of libsp.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I94460dc03dd6dcd27f6865f852cc9a0d85f4b583
diff --git a/components/messaging/ffa/libsp/mock/component.cmake b/components/messaging/ffa/libsp/mock/component.cmake
index 03b8006..15db85a 100644
--- a/components/messaging/ffa/libsp/mock/component.cmake
+++ b/components/messaging/ffa/libsp/mock/component.cmake
@@ -12,6 +12,7 @@
 	"${CMAKE_CURRENT_LIST_DIR}/mock_assert.cpp"
 	"${CMAKE_CURRENT_LIST_DIR}/mock_ffa_api.cpp"
 	"${CMAKE_CURRENT_LIST_DIR}/mock_ffa_internal_api.cpp"
+	"${CMAKE_CURRENT_LIST_DIR}/mock_sp_discovery.cpp"
 	"${CMAKE_CURRENT_LIST_DIR}/mock_sp_rxtx.cpp"
 	)