drm/nouveau/disp/sor/gf119: both links use the same training register

drm/nouveau/disp/sor/gf119: both links use the same training register

BugLink: http://bugs.launchpad.net/bugs/1607404
commit a8953c52b95167b5d21a66f0859751570271d834 upstream.

It appears that, for whatever reason, both link A and B use the same
register to control the training pattern.  It's a little odd, as the
GPUs before this (Tesla/Fermi1) have per-link registers, as do newer
GPUs (Maxwell).

Fixes the third DP output on NVS 510 (GK107).

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>