[EFL] Move DATA_INSTALL_DIR to ewebkit2-0
https://bugs.webkit.org/show_bug.cgi?id=135553

Reviewed by Gyuyoung Kim.

Since WebKit1/Efl is dropped, we don't need to use ewebkit-1 and ewebkit2-1.
And removed WebKit_OUTPUT_NAME variable which is not used anymore on the EFL port.

* Source/cmake/OptionsEfl.cmake:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@171985 268f45cc-cd09-0410-ab3c-d52691b4dbfc