chcpu: new tool

chcpu: new tool

chcpu can modify the logical state of CPUs. It can enable and disable CPUs,
scan for new CPUs, change the CPU dispatching mode of the underlying
hypervisor and request (configure) or give logical CPUs back (deconfigure)
to the the underlying hypervisor.

This is quite useful if you work a lot with virtual servers, since doing all
the configuration stuff directly via sysfs becomes a pain.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>