s390/pai_crypto: Merge pai_ext PMU into pai_crypto

s390/pai_crypto: Merge pai_ext PMU into pai_crypto

Combine PAI cryptography and PAI extension (NNPA) PMUs in one driver.
Remove file perf_pai_ext.c and registration of PMU "pai_ext"
from perf_pai_crypto.c.

Includes:
- Shared alloc/free and sched_task handling
- NNPA events with exclude_kernel enforced, exclude_user rejected
- Setup CR0 bits for both PMUs

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>