[EFL] Fix build when DRAG_SUPPORT is set OFF
https://bugs.webkit.org/show_bug.cgi?id=117628

Patch by Michał Pakuła vel Rutka <m.pakula@samsung.com> on 2013-06-14
Reviewed by Gyuyoung Kim.

Add guard around Clipboard::declareAndWriteDragImage.

* platform/efl/ClipboardEfl.cpp:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@151582 268f45cc-cd09-0410-ab3c-d52691b4dbfc