net: sparx5: use library helper for freeing tx buffers

The library has the helper fdma_free_phys() for freeing physical FDMA
memory. Use it in the exit path.
Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
Reviewed-by: Jens Emil Schulz Østergaard <jensemil.schulzostergaard@microchip.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/sparx5/sparx5_fdma.c

@@ -494,5 +494,6 @@ int sparx5_fdma_stop(struct sparx5 *sparx5)
 			  FDMA_PORT_CTRL_XTR_BUF_IS_EMPTY_GET(val) == 0,
 			  500, 10000, 0, sparx5);
 	fdma_free_phys(&sparx5->rx.fdma);
+	fdma_free_phys(&sparx5->tx.fdma);
 	return 0;
 }