qlcnic: VF-PF communication channel implementation

o Adapter provides communication channel between VF and PF.
  Any control commands from the VF driver are sent to the PF driver
  through this communication channel. PF driver validates the
  commands before sending them to the adapter. Similarly PF driver
  forwards any control command responses  to the VF driver
  through this communication channel.  Adapter sends message pending
  event to VF or PF when there is an outstanding response or a command
  for VF or PF respectively. When a command or a response is sent over
  a channel VF or PF cannot send another command or a response
  until adapter sends a channel free event. Adapter allocates 1K area to
  VF and  PF each for this communication.
o Commands and  responses are encapsulated in a header. Header determines
  sequence id, number of fragments, fragment number etc.

Signed-off-by: Manish Chopra <manish.chopra@qlogic.com>
Signed-off-by: Sucheta Chakraborty <sucheta.chakraborty@qlogic.com>
Signed-off-by: Rajesh Borundia <rajesh.borundia@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>