CMake: Move hal stubs sources to the mbed-os/hal directory

Move the hal stubs into the hal component directory.
so we can avoid duplicating the mbed-os source tree in a central
UNITTESTS folder.

UNITTESTS/stubs/CMakeLists.txt

@@ -109,7 +109,6 @@ target_include_directories(mbed-stubs-headers
 
 add_subdirectory(connectivity)
 add_subdirectory(events)
-add_subdirectory(hal)
 add_subdirectory(platform)
 add_subdirectory(storage)
 

hal/CMakeLists.txt

@@ -1,6 +1,10 @@
 # Copyright (c) 2020-2021 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(TARGET_FLASH_CMSIS_ALGO EXCLUDE_FROM_ALL)
 
 add_subdirectory(usb)

hal/tests/.mbedignore

@@ -0,0 +1 @@
+UNITTESTS/*

hal/tests/UNITTESTS/CMakeLists.txt

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