ARM: dts: msm: Enable msm boot stats

Enable msm boot stats for by adding the MPM
sleep counter node, which is needed to report msm
boot stats such as bootloader throughput, total boot
time, etc.

Change-Id: I0d25a6b6b0e99462f476d9f3152b0eabc064c976
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>