qemu.test: Add cpuinfo_query test

1). cpuid query
2). cpu model query
3). cpu dump file quey
4). supported machine type query

Change from v1:
1). cpuid, model, dump query is not supported in rhel5, add the limitation
2). rhel5 machine type is diff from rhel6

Change from v2:
add rhel6.3 machine type configuration

Change from v3:
add default value to cpuinfos
add query_cmd notification

Change from v4:
update utils.cmd to utils.system_output

Signed-off-by: Suqin Huang <shuang@redhat.com>