qlcnic: Enable multiple Tx queue support for 83xx/84xx Series adapters.

o 83xx and 84xx firmware is capable of multiple Tx queues.
  This patch will enable multiple Tx queues for 83xx/84xx
  series adapters. Max number of Tx queues supported will be 8.

Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>