Texture functions TFUNC_FRAGMENT_DOUBLE_TEXTURE_EFECT_UNKNOWx have the same behavior as TFUNC_FRAGMENT_DOUBLE_TEXTURE_EFECT_ADD. Tested on PSP using 3DStudio.

git-svn-id: http://jpcsp.googlecode.com/svn/trunk@3423 4ab978e6-3352-0410-996c-0b42db0051c8