bt: Fix unit tests build with CMake

components/bt/test/CMakeLists.txt

@@ -1,8 +1,7 @@
-if(CONFIG_BT_ENABLED)
+if(CONFIG_BT_ENABLED OR CMAKE_BUILD_EARLY_EXPANSION)
     set(COMPONENT_SRCDIRS ".")
     set(COMPONENT_ADD_INCLUDEDIRS ".")
+    set(COMPONENT_REQUIRES unity nvs_flash bt)
+
+    register_component()
 endif()
-
-set(COMPONENT_REQUIRES unity nvs_flash bt)
-
-register_component()