qed: Reserve doorbell BAR space for present CPUs

Reserving doorbell BAR space according to the currently active CPUs
may result in a bug if disabled CPUs are later enabled but no
doorbell space was reserved for them.

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