cpumf: Add short description for z13 extended counter set
cpumf: Add short description for z13 extended counter set

Add a short description to the z13 extended counter set
definition file.

Signed-off-by: Thomas Richter <8efd8ac704d21550d1708b5fda9fd8afae04d143@linux.vnet.ibm.com>
Reviewed-by: Hendrik Brueckner <ea0a2d16c17dd61debc108adbc0ac849646dd099@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <96138615ab4af0813785fa10d283f3d37eca3b78@linux.ibm.com>

ibm-s390-tools/s390-tools,ibm-s390-tools/s390-tools,ibm-s390-tools/s390-tools,ibm-s390-tools/s390-tools