net: macb: Free RX ring for all queues

rx ring is allocated for all queues in macb_alloc_consistent.
Free the same for all queues instead of just Q0.

Signed-off-by: Harini Katakam <harini.katakam@xilinx.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>