CMake: Move nanostack libservice stubs to the connectivity/libraries dir

Move the connectivity nanostack-libservice stubs into the connectivity/libraries
directory where the nanostack libservice component present as nanostack
libservice source copied from the external repo. So we can avoid duplicating
the mbed-os source tree in a central UNITTESTS folder.

Author: rajkan01

UNITTESTS/stubs/CMakeLists.txt

@@ -48,13 +48,10 @@ target_include_directories(mbed-stubs-headers
         .
 )
 
-add_subdirectory(connectivity)
-
 add_library(mbed-stubs INTERFACE)
 
 target_link_libraries(mbed-stubs
     INTERFACE
-        mbed-stubs-connectivity
         mbed-stubs-drivers
         mbed-stubs-events
         mbed-stubs-hal

UNITTESTS/stubs/connectivity/CMakeLists.txt

@@ -42,4 +42,5 @@ else()
     add_subdirectory(lorawan)
     add_subdirectory(netsocket)
     add_subdirectory(mbedtls)
+    add_subdirectory(libraries)
 endif()

connectivity/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME AND BUILD_TESTING)
+    add_subdirectory(tests/UNITTESTS)
+endif()
+
 add_subdirectory(mbed-coap)
 add_subdirectory(nanostack-libservice)
 add_subdirectory(ppp)

connectivity/libraries/CMakeLists.txt

@@ -0,0 +1 @@
+*

connectivity/libraries/tests/UNITTESTS/.mbedignore

@@ -0,0 +1,4 @@
+# Copyright (c) 2021 ARM Limited. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+add_subdirectory(doubles)

connectivity/libraries/tests/UNITTESTS/CMakeLists.txt

@@ -0,0 +1,20 @@
+# Copyright (c) 2021 ARM Limited. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+add_library(mbed-stubs-nanostack-libservice)
+
+target_sources(mbed-stubs-nanostack-libservice
+    PRIVATE
+        ip4tos_stub.c
+        stoip4_stub.c
+)
+
+target_link_libraries(mbed-stubs-nanostack-libservice
+    PRIVATE
+        mbed-stubs-rtos-headers
+        mbed-headers
+        mbed-stubs-headers
+        mbed-stubs-rtos
+        mbed-stubs-platform
+        gtest
+)