evas: use a tricky NULL texture.
evas: use a tricky NULL texture.

Note: this help the driver to know that we don't it
to swizzle back the pixel from GPU format, because we
are going to replace all pixels.


git-svn-id: 6d771e449150288cc513807b7f4d2af31e9482bd@63201 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33

TizenChameleon/evas,TizenChameleon/uifw-evas,TizenChameleon/uifw-evas,TizenChameleon/evas,TizenChameleon/evas,TizenChameleon/uifw-evas,TizenChameleon/evas,TizenChameleon/uifw-evas