st/mesa: attempt to fix TFP by using sampler views (v1)

st/mesa: attempt to fix TFP by using sampler views (v1)

Okay I think this is good enough for now, I can't see any other reason
for mesa to want to use a sampler view so lets just leave it at all the A->X conversions for now.

I've been running gnome-shell under r300g with this for day or so and it seems fine.

Signed-off-by: Dave Airlie <airlied@redhat.com>