perf_cpum_cf: Add support for counters available with IBM zEC12

Increase the maximum number of available counters and check if
the hardware supports the counter.  Support is indicated by the
version of the CPU-measurement counter facility.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>