qlcnic: Add PVID support for 84xx adapters

o 84xx adapters support VLAN stripping for PVID. Packets don't have
  VLAN tag inserted in case of PVID. So packet should follow non vlan path.

o Use capability bit to set PVID mode.

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>