staging: unisys: visorbus: allow visorhba device to be used for kdump

This patch saves off the create_bus and create_device controlvm messages
for the visorhba device, so that they can be resurrected and used in the
kdump kernel.

After this patch, a crash dump can be generated using:

    # service kdump start
    # echo 1 > /proc/sys/kernel/sysrq
    # echo c > /proc/sysrq-trigger

Signed-off-by: Timothy Sell <timothy.sell@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>