nv50_head_atomic_duplicate_state() makes a copy of nv50_head_atom
struct. This patch adds copying of struct member named "or", which
previously was left uninitialized in the duplicated structure.

Due to this bug, incorrect nhsync and nvsync values were sometimes used.
In my particular case, that lead to a mismatch between the output
resolution of the graphics device (GeForce GT 630 OEM) and the reported
input signal resolution on the display. xrandr reported 1680x1050, but
the display reported 1280x1024. As a result of this mismatch, the output
on the display looked like it was cropped (only part of the output was
actually visible on the display).

git bisect pointed to commit 2ca7fb5c ("drm/nouveau/kms/nv50: handle
SetControlOutputResource from head"), which added the member "or" to
nv50_head_atom structure, but forgot to copy it in
nv50_head_atomic_duplicate_state().

Fixes: 2ca7fb5c ("drm/nouveau/kms/nv50: handle SetControlOutputResource from head")
Signed-off-by: Peteris Rudzusiks <peteris.rudzusiks@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>