s390/cio: export measurement data for all CMGs

A channel-path's channel-measurement-group value (CMG) determines the
format of associated measurement data and characteristics blocks. Both
blocks are of fixed size and contain a generic and CMG-dependent part.

Currently CIO exports these data blocks via sysfs only for a specific
list of CMGs even though the kernel itself does not interpret
CMG-dependent data.

Change CIO to export measurement data and characteristics for all CMGs.
This enables supporting new CMG data formats in userspace without the
need for kernel changes.

Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>