qed: Improve VF interrupt reset

During FLR flow, need to make sure HW is no longer capable of writing to
host memory as part of its interrupt mechanisms.
While we're at it, unify the logic cleaning the driver's status-blocks
into using a single API function for both PFs and VFs.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>