s390/ap: filter ap card functions, new queue functions attribute

With SE SB (Secure Binding) some currently unused and thus always
zero bits in the TAPQ GR2 result are now used to show the binding
state of a queue. So to check if a card has changed the comparing
base is exactly this GR2 value shown as 'ap_function' in sysfs
(/sys/devices/ap/cardxx/ap_functions). Now there is some queue
specific info in this info and so a new mask TAPQ_CARD_FUNC_CMP_MASK
is used to filter out only the relevant bits for card compare.

For the same reason now the function bits (including exactly this
bind/associate information) need to be exposed to user space now.
So tools like lszcrypt can evaluate binding/association state on a
queue base. So here comes a new sysfs attribute

  /sys/devices/ap/cardxx/xx.yyyy/ap_functions

This sysfs attribute is similar to the already existing
ap_functions attribute at ap card level. It shows the
upper 32 bits of GR2 from an invocation of TAPQ for this
AP queue.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>