[CMake] Fix dependecy calculation for generated inspector files
https://bugs.webkit.org/show_bug.cgi?id=114092

Reviewed by Brent Fulgham.

At least in a generated Visual Studio solution the files generated via
CodeGeneratorInspector.py are considered outdated all the time because
the code generator only touches the file when the content changed.
Add an --write_always parameter to the script to touch the file always.

* CMakeLists.txt:
* inspector/CodeGeneratorInspector.py:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148586 268f45cc-cd09-0410-ab3c-d52691b4dbfc