s390x/gdb: Split s390-virt.xml

s390x/gdb: Split s390-virt.xml

Both TCG and KVM emulate ckc, cputm, last_break and prefix, and it's
quite useful to have them during debugging. Right now they are grouped
together with KVM-only pp, pfault_token, pfault_select and
pfault_compare in s390-virt.xml, and are not available when debugging
TCG-emulated code.

Move KVM-only registers into the new s390-virt-kvm.xml file. Advertise
s390-virt.xml always, and the new s390-virt-kvm.xml only for KVM.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230314101813.174874-1-iii@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>