This ports the workaround from radeonsi, that was missing in radv.
This fixes Talos rendering when MSAA is enabled on my Tahiti card.
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Fixes: f4e499ec7 (radv: add initial non-conformant radv vulkan driver)
Signed-off-by: Dave Airlie <airlied@redhat.com>