CMake: Fix linking of greentea, unity and utest

The test application uses the greentea client for synchronization
with the host and unity for assertions, and unity in Mbed OS contains
references to utest. We have recently split them from one
mbed-greentea library into three, so the test application needs to
link all of them.

Author: LDong-Arm

CMakeLists.txt

@@ -43,7 +43,10 @@ target_link_libraries(${APP_TARGET}
     PRIVATE
         mbed-os
         mbed-psa
-        mbed-greentea
+        mbed-unity
+        mbed-utest
+        mbed-greentea-io
+        greentea::client_userio
 )
 
 if ("${MBED_CONFIG_DEFINITIONS}" MATCHES "MBED_CONF_APP_REGRESSION_TEST=1")