commit a90e049c upstream.

GP102's cursors go from chan 17..20. Increase the array size to hold
their data properly.

Fixes: e50fcff1 ("drm/nouveau/disp/gp102: fix cursor/overlay immediate channel indices")
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>