r600/sfn: sort FS color outputs before all other outputs

r600/sfn: sort FS color outputs before all other outputs

The color outputs must be checked against the number of available
color buffers, therefore it is best to sort the color outputs to be
on the driver locations before the other FS outputs.

Fixes: 79ca456b4837b3bc21cf9ef3c03c505c4b4909f6
   r600/sfn: rewrite NIR backend

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/7530

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19804>
(cherry picked from commit be570cd32254f1360e5010d091eea142b3990e72)