CMake: Fix escaping of quotes in response file

We put macros in a response file compile_time_defs.txt and pass it
to the compiler. Adding a pair of single quotes around each -D flag
ensures macro values are quoted correctly.

For example,
* String
  * target_compile_definitions(): either FOO="BAR" or FOO=\"BAR\"
  * response file: '-DFOO="BAR"'
  * actual definition: #define FOO "BAR"
* Array of integers
  * target_compile_definitions(): FOO={1, 2, 3}
  * response file: 'FOO={1, 2, 3}'
  * actual definition: #define FOO {1, 2, 3}

tools/cmake/mbed_toolchain.cmake

@@ -7,17 +7,9 @@ function(mbed_generate_options_for_linker target output_response_file_path)
         "$<TARGET_PROPERTY:${target},INTERFACE_COMPILE_DEFINITIONS>"
     )
 
-    # Remove macro definitions that contain spaces as the lack of escape sequences and quotation marks
-    # in the macro when retrieved using generator expressions causes linker errors.
-    # This includes string macros, array macros, and macros with operations.
-    # TODO CMake: Add escape sequences and quotation marks where necessary instead of removing these macros.
+    # Append -D to all macros and quote them as we pass these as response file to cxx compiler
     set(_compile_definitions
-       "$<FILTER:${_compile_definitions},EXCLUDE, +>"
-    )
-
-    # Append -D to all macros as we pass these as response file to cxx compiler
-    set(_compile_definitions
-        "$<$<BOOL:${_compile_definitions}>:-D$<JOIN:${_compile_definitions}, -D>>"
+        "$<$<BOOL:${_compile_definitions}>:'-D$<JOIN:${_compile_definitions},' '-D>'>"
     )
     file(GENERATE OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/compile_time_defs.txt" CONTENT "${_compile_definitions}\n")
     set(${output_response_file_path} @${CMAKE_CURRENT_BINARY_DIR}/compile_time_defs.txt PARENT_SCOPE)