soc: qcom: hab: benchmark cross VM schdule latency

Develop a mechanism to measure the latency of cross-vm scheduling.
It makes use of mpm_timer and leverage hab driver to record the time
when previous vm is scheduled out and when next vm is schduled in,
and pass these values to habtest to calculate the latency of schduling.

Change-Id: I0051d5a42979826b8e249ac704fcc7ed87d8d581
Signed-off-by: Chao Bi <chaobi@codeaurora.org>