s390/ap: add card/queue deconfig state

This patch adds a new config state to the ap card and queue
devices. This state reflects the response code
0x03 "AP deconfigured" on TQAP invocation and is tracked with
every ap bus scan.

Together with this new state now a card/queue device which
is 'deconfigured' is not disposed any more. However, for backward
compatibility the online state now needs to take this state into
account. So a card/queue is offline when the device is not configured.
Furthermore a device can't get switched from offline to online state
when not configured.

The config state is shown in sysfs at
  /sys/devices/ap/cardxx/config
for the card and
  /sys/devices/ap/cardxx/xx.yyyy/config
for each queue within each card.
It is a read-only attribute reflecting the negation of the
'AP deconfig' state as it is noted in the AP documents.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>