anv: use image aspects rather than computed ones

anv: use image aspects rather than computed ones

This shouldn't make any difference but I feel uneasy to use the
expanded aspects that do not represent the image in its entirety. If
we ever change the implementation of the anv_image_aspect_to_plane()
helper, this is safer.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>