net/mlx4_core: Handle AER flow properly

Fix AER callbacks to work properly, it includes:
- Refractoring AER to be aligned with Reset flow support.
- Sync with concurrent catas flow.

In addition, fix the shutdown PCI callback to sync with
concurrent catas flow.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>