ARM: dts: msm: Add power management devices for MSM8994

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

Change-Id: Ifc5d941fbd31faa56206ea81f0c894f8fc3e9e67
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>