s390/pai: Deny all events not handled by this PMU

Each PAI PMU device driver returns -EINVAL when an event is out of
its accepted range. This return value aborts the search for an
alternative PMU device driver to handle this event.
Change the return value to -ENOENT. This return value is used to
try other PMUs instead.  This makes the PMUs more robust when
the sequence of PMU device driver initialization changes (at boot time)
or by using modules.

Fixes: 39d62336 ("s390/pai: add support for cryptography counters")
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>