igc: Check incompatible configs for Frame Preemption

Frame Preemption and LaunchTime cannot be enabled on the same queue.
If that situation happens, emit an error to the user, and log the
error.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>

drivers/net/ethernet/intel/igc/igc_main.c

@@ -5916,6 +5916,11 @@ static int igc_save_launchtime_params(struct igc_adapter *adapter, int queue,
 	if (queue < 0 || queue >= adapter->num_tx_queues)
 		return -EINVAL;
 
+	if (ring->preemptible) {
+		netdev_err(adapter->netdev, "Cannot enable LaunchTime on a preemptible queue\n");
+		return -EINVAL;
+	}
+
 	ring = adapter->tx_ring[queue];
 	ring->launchtime_enable = enable;