msm: rpm-stats: Add version 2 support for RPM Stats

Read RPM sleep stats from the RPM DATA RAM and print it to
user buffer. Version 2 reads different message layout from RPM
Data RAM as compared to version 1 and also exports additional
sleep statistics.

CRs-fixed: 408805
Change-Id: If3913e55cf702da04a0cc563a73a0002cdc42a42
Signed-off-by: Priyanka Mathur <pmathur@codeaurora.org>