CMake: Add more information to TODO comment

Author: rajkan01

connectivity/netsocket/CMakeLists.txt

@@ -1,7 +1,7 @@
 # Copyright (c) 2020 ARM Limited. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
-# TODO CMake: Perhaps move this/these file(s)
+# TODO CMake: Perhaps move this/these file(s) into connectivity/drivers/cellular
 target_sources(mbed-cellular
     INTERFACE
         source/CellularNonIPSocket.cpp