guest-os: Add rhel64 ppc config

Adds the configuration file for rhel64 guest os.
Helps the config parser to use the only RHEL.6.4.ppc64 filter.
Need to validate the unattattend install through this ks file.

Signed-off-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Reviewed-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>
virt: docstring fix

docstring fix for the param in virt tests

Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>