utils: Add fallback for missing cpu values

read model name from "/proc/cpuinfo" when miss "Model name" line of "lscpu" output

Change-Id: Id397d3c02dcc1c3bf0fa16ea2c9b816fef1e213f
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1129598
Signed-off-by: hadong <hadong@redhat.com>
Signed-off-by: Fabian Deutsch <fabiand@fedoraproject.org>