anv/image: Use RENDER_SURFACE_STATE::X/Y Offset on SKL+

anv/image: Use RENDER_SURFACE_STATE::X/Y Offset on SKL+

The Broadwell method of handling uncompressed views of compressed
textures was to make the texture linear and have a tiled shadow copy.
This isn't needed on Sky Lake because the HALIGN and VALIGN parameters
are specified in surface elements and required to be a multiple of 4.
This means that we can just use the X/Y Offset fields and we can avoid
the shadow copy song and dance.  This also makes ASTC work because ASTC
can't be linear and so the shadow copy method doesn't work there.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>