st/nine: Fix support for ps 1.4 dw and dz modifiers

RCP was used incorrectly to support NINED3DSPSM_DW and
NINED3DSPSM_DZ. src.x was used as input instead of src.w
or src.z.

Fixes: https://github.com/iXit/Mesa-3D/issues/271

Signed-off-by: Axel Davy <axel.davy@ens.fr>
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
1 file changed