radv/gfx9: only minify image view width/height/depth before gfx9.

radv/gfx9: only minify image view width/height/depth before gfx9.

For gfx9 the addressing for images has changed, so we need to
provide the hw with the level0, however we still need to scale
for format block differences (so our compressed upload paths still
work).

Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Cc: "17.2" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>