bnx2x: AER revised

Revised bnx2x implementation of PCI Express Advanced Error Recovery -
stop and free driver resources according to the AER flow (instead of the
currently implemented `hope-for-the-best' release approach), and do not make
any assumptions on the HW state after slot reset.

Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Ariel Elior <ariele@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>