net: fec: Add Ftype to BD to distiguish three tx queues for AVB

The current driver loss Ftype field init for BD, which cause tx
queue #1 and #2 cannot work well.

Add Ftype field to BD to distiguish three queues for AVB:
0 -> Best Effort
1 -> ClassA
2 -> ClassB

Signed-off-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>