egl: Wrap dri3 surface primitive around dri2 egl surface

egl: Wrap dri3 surface primitive around dri2 egl surface

Originally dri3 egl surface was wrapped around _EGLSurface.

With next commit we'll add additional attributes, which will be checked
from generic code. Thus in order to access that we need to use
dri2_egl_surface.

The name of the latter is a misnomer - it should really be dri or
dri_common...

Signed-off-by: Yogesh Marathe <yogesh.marathe@intel.com>
[Emil Velikov: commit message, squash the patches appropriately, add
relevant _eglInitSurface hunk to prevent build breakage]
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>