s390x/kvm: passing max memory size to accelerator

With "KVM: s390: Allow userspace to limit guest memory size" KVM is able to
do some optimizations based on the guest memory limit.

The guest memory limit is computed by the initial definition and with the notion of
hotplugged memory.

Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Guenther Hutzl <hutzl@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Message-Id: <1425570981-40609-3-git-send-email-jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
