Wire up disabled wait a panicked event on s390

On s390 the disabled wait state indicates a state of attention.
For example Linux uses that state after a panic. Lets
put the system into panicked state.

An alternative implementation would be to state
disabled-wait <address> instead of pause in the action field.
(e.g. z/OS, z/VM and other classic OSes use the address of the
disabled wait to indicate an error code).

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 6cf41156322e27e81a727b69f03728dbc225d5bb.1366945969.git.hutao@cn.fujitsu.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
