qlcnic: Reinitialize mailbox data structures after firmware reset

o After firmware reset VFs were failing to come up because of not
  reinitializing mailbox data structures. Reinitialize them so that
  VFs can come up after firmware reset.

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