This is needed to implement the EXT_EGL_image_storage spec:
"If <target> is GL_TEXTURE_2D, then the resultant texture must have a
sized internal format which is colorspace and size compatible with the
dma-buf. If the GL is unable to determine such a format, the error
INVALID_OPERATION is generated."
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>