s390x/cpu: Use ioctl to reset state in the kernel

s390x/cpu: Use ioctl to reset state in the kernel

Some of the state in the kernel can not be reset from QEMU yet.
For this we've got to use the KVM_S390_INITIAL_RESET ioctl to make
sure that the state in the kernel is set to the right values during
initial CPU reset, too.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>