soc: qcom: hab: add performance test mechanism for HAB

Develop a mechanism to faciliate the performance test for hab
and share memory.
Use "echo 0 > /sys/module/msm_hab/parameters/perf_test" to
start share memory throughput test, and use
"cat /sys/module/msm_hab/parameters/perf_test" to get the
result.

Change-Id: Ic9e27ace5332bd022e444747ab58152bb3dfd584
Signed-off-by: Chao Bi <chaobi@codeaurora.org>