KVM: s390: Add architectural trace events

Add trace events for several s390 architecture specifics:

- SIE entry/exit
- common intercepts
- common instructions (sigp/diagnose)

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>