bnx2: Enable AER on PCIE devices only

To prevent unnecessary error message.  pci_save_state() is also moved to
the end of ->probe() so that all PCI config, including AER state, will be
saved.

Update version to 2.0.18.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Reviewed-by: Benjamin Li <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>