ARM: dts: msm: Add power management devices for MSM8994v2

Add DT entries for SPM devices for CCI/L2/CPU levels. Also add
lpm-levels node to support hierarchical cluster low power modes.

Change-Id: I03dbe0a4090d8144c5adb14bede908743f6a6246
Signed-off-by: Karthik Parsha <kparsha@codeaurora.org>