radv: Delay patching for imported images until layout time.

radv: Delay patching for imported images until layout time.

We want this flexibility because in GFX10 we lose any stride fields,
so we have to make sure our width/height are in alignment with
the external image we import.

Furthermore, we need the ability to inject tiling modifiers on import
time which is strictly after create time for Android. So, with the
layout & patch functions being fully independent of pCreateInfo, we
can delay it until import/bind time.

Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>