ARM: dts: msm8992: Enable HMP scheduler

Enable the HMP scheduler for msm8992 to fully utilize the power and
performance benefits with Big/Little architecture. For more information
about HMP scheduler please see Documentation/scheduler/sched-hmp.txt.

Change-Id: Ibedc0525cc68943b5f85cc4f2e37dc2184751f6a
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>