radv: move spi_baryc_cntl to pipeline

We need to enable the pos float location 2 mode anytime we have
persample not just when forced by the frag shader.

This fixes:
dEQP-VK.pipeline.multisample.min_sample_shading*

Fixes: 58c97a07 (radv: enable location at sample when persample is forced.)
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit 29855454)