msm: pm-stats: refactor pm-stats into its own file

pm-stats records the time spent in each low power mode. The stats can be
accessed from /proc/msm_pm_stats. Refactor stats into pm-stats.c and
export only the required functions.

Also, remove CONFIG_MSM_IDLE_STATS blocks around code in pm-8x60.c and
pm2.c

pm-stats.c can optionally be compiled out completely.

Change-Id: Ie8fae1d0b2c53e2fbb92f3baf70efd9d33af27ae
Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>
Signed-off-by: Anji jonnala <anjir@codeaurora.org>
6 files changed