radeonsi/gfx9: fix most things wrong with shader images

radeonsi/gfx9: fix most things wrong with shader images

There are 2 major hw changes:
- The address must always point to the address of level 0. GFX9 tiling
  modes don't allow binding to a non-0 level.
- 3D must always be bound as 3D, because 2D and 3D use entirely different
  tiling modes, and the texture target determines which set of modes is
  used.

Cc: 17.1 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>