anv/cmd_buffer: Add a mark_image_written helper

anv/cmd_buffer: Add a mark_image_written helper

Currently, this helper does nothing but we call it every place where an
image is written through the render pipeline.  This will allow us to
properly mark the aux state so that we can handle resolves correctly.

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Nanley Chery <nanley.g.chery@intel.com>