R6xx has routable blocks, but there's nothing wrong in assignment based
on dig_encoder. We didn't really need that algorithm.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com> Tested-by: Christian König <deathsimple@vodafone.de> Reviewed-by: Christian König <deathsimple@vodafone.de> Signed-off-by: Dave Airlie <airlied@redhat.com>