qlcnic: Interrupt based driver firmware mailbox mechanism

o Driver firmware mailbox interface was operating in polling mode
  because of limitations with the earlier versions of 83xx adapter firmware.
  These issues are resolved and we are implementing interrupt based mailbox
  mechanism.

o Data structures and API's for interrupt mode mailbox mechanism.

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