drm/radeon/kms: fix prescale calculations

Pre-pcie chips seem to use the reference clock
rather than the sclk.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Alex Deucher 2010-02-08 14:34:43 -05:00 • committed by Dave Airlie
commit 9dad76e8be