s390/ap: Add functiton facility information as AP device attribute.

Add the function facility information as new ap_device and sysfs
attribute. Also make the number of requests in device
queue and in device driver queue accessible in sysfs.

Reviewed-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>