hlte: power enhancement for wacom hardware.

* always disable digitizer when the pen is inserted

Change-Id: I6c9798682f9f6349b37cb452353bd0c0e6958401
PM / devfreq: Fix simple_ondemand crashing
PM: devfreq: Fix show available freqs
PM: devfreq: Use high priority workqueue

It does not make sense to run kgsl on high and devfreq on regular
priority.
msm: kgsl: Use high priority workqueue
msm: clock-krait-8974: User voltage control for msm-cpufreq device
logger: Add an enable toggle for entry storage
PM: devfreq: Fixup device transition and usage statistics

Ignore bogus data during slumber in transition and usage stats that
rendered the output basically useless. Also fix the reported GPU
frequency.
dts: add msm8974pro frequency
msm: kgsl: Report correct GPU frequency in sysfs
msm_thermal: small cleanup