bnx2x: Disable VF access on PF removal

bnx2x: Disable VF access on PF removal

When the bnx2x driver is rmmoded, if VFs of a given PF will be assigned
to a VM then that PF will be unable to call `pci_disable_sriov()'.

If for that same PF there would also exist unassigned VFs in the hypervisor,
the result will be that after the removal there will still be virtual PCI
functions on the hypervisor.
If the bnx2x module were to be re-inserted, the result will be that the VFs
on the hypervisor will be re-probed directly following the PF's probe, even
though that in regular loading flow sriov is only enabled once PF is loaded.
The probed VF will then try to access its bar, causing a PCI error as the HW
is not in a state enabling such a request.

This patch adds a missing disablement procedure to the PF's removal, one that
sets registers viewable to the VF to indicate that the VFs have no permission
to access the bar, thus resulting in probe errors instead of PCI errors.

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