PM: devfreq: Use high priority workqueue

It does not make sense to run kgsl on high and devfreq on regular
priority.
dts: adjust thermal sensor and temperature
msm: thermal: Relax temperature thresholds

Relax temperature thresholds, the device is constantly throttling.
Also, use core control to avoid physical damage, not temperature
control.
arm/dt: msm8974: Lower GPU voltage constraints
board-8974: enable ram console

by imoseyon