List some case only Host_RHEL.6
Do not run these case in RHEL3, RHEL4 guest.
Reconfig qmp_query-mice test case.
Rename qmp_device_add to qmp_redhat_device_add.
Re-design qmp_command.qmp_query-version test case
Signed-off-by: NFeng Yang <fyang@redhat.com>