drivers: net: xgene: Add support for multiple queues

Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: Khuong Dinh <kdinh@apm.com>
Signed-off-by: Tanmay Inamdar <tinamdar@apm.com>
Tested-by: Toan Le <toanle@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>