drm/nouveau: bump fence timeout to 15 seconds

calim didn't like 150 seconds timeout, so lower the timeout for him.
15 seconds should still be plenty.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_fence.c

@@ -143,7 +143,7 @@ nouveau_fence_emit(struct nouveau_fence *fence, struct nouveau_channel *chan)
 	int ret;
 
 	fence->channel  = chan;
-	fence->timeout  = jiffies + (3 * DRM_HZ);
+	fence->timeout  = jiffies + (15 * DRM_HZ);
 	fence->sequence = ++fctx->sequence;
 
 	ret = fctx->emit(fence);