KVM: s390: Provide global debug log

In addition to the per VM debug logs, let's provide a global
one for KVM-wide events, like new guests or fatal errors.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>

diff --cc arch/s390/include/asm/kvm_host.h
Simple merge

diff --cc arch/s390/kvm/kvm-s390.c
Simple merge

diff --cc arch/s390/kvm/kvm-s390.h
Simple merge