Evas GL: Skip FBO creation when direct_mem_opt is set, unless direct fallback is...

Evas GL: Skip FBO creation when direct_mem_opt is set, unless direct fallback is set.

Summary:
When direct_mem_opt is set, FBO should not be created, unless
the render target for direct rendering is FBO.
There are cases where evas_gl_make_current is called outside
on pixel callback in webkit, and since they use direct_mem_opt,
FBO is repeatedly created/destroyed during switch from direct to indirect.
This should fix it.

@tizen_fix : bug fix

Change-Id: I5e73913069f2b214e0cbd0e7136d1221ed0fb95c