perf: add scripts to collect guest/host sysinfo

This is prepared for RHEL OS, others can write their own scripts
to collect what they want to get.

These two scripts are examples.

Signed-off-by: Amos Kong <akong@redhat.com>

The two script be used by netperf.py, you can find detail in https://github.com/autotest/tp-qemu/pull/35