* docs/schemas/domain.rng (sysinfo-system-name): Also allow
family.
* src/util/sysinfo.h (struct _virSysinfoDef): Add system_family.
* src/conf/domain_conf.c (virSysinfoParseXML)
(virDomainSysinfoDefFormat): Support it.
* src/util/sysinfo.c (virSysinfoDefFree, virSysinfoRead): Likewise.
* src/qemu/qemu_conf.c (qemuBuildSmbiosSystemStr): Likewise.
* tests/qemuxml2argvdata/qemuxml2argv-smbios.xml: Adjust test.
* tests/qemuxml2argvdata/qemuxml2argv-smbios.args: Likewise.