Add a utils for hugepages test.

During the hugepage test, we need to set the transparent hugepage, get the
transparent hugepage state, prepare a c file for test.
This utils contain those funcitons.

Signed-off-by: Weiqing Wang <wangwq.fnst@cn.fujitsu.com>
I had check virttest/test_setup.py. I don't think that is fit my request.So I wrote those functions.