[CMake] Remove invalid include paths
https://bugs.webkit.org/show_bug.cgi?id=116213

Reviewed by Gyuyoung Kim.

Since "${JAVASCRIPTCORE_DIR}/wtf" does not exist, it is safe
to remove them from the list of include directories.

Source/JavaScriptCore:

* PlatformEfl.cmake: Removed.
* PlatformGTK.cmake: Removed.

Source/WTF:

* wtf/PlatformEfl.cmake:
* wtf/PlatformGTK.cmake:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@150253 268f45cc-cd09-0410-ab3c-d52691b4dbfc