[PATCH v4] Thermal cleanups and hardware trip points

[Sascha Hauer]

This series adds support for hardware trip points. It picks up earlier
work from Mikko Perttunen. Mikko implemented hardware trip points as part
of the device tree support. It was suggested back then to move the
functionality to the thermal core instead of putting more code into the
device tree support. This series does exactly that.

The majority of the patches are cleanups and fixes. Patch 11 introduces
hardware tracked trip points and finally a driver for the Mediatek
thermal controller is introduced as the first user.

All comments welcome

Changes since v3:
- Fix some missing function type changes in int3400_thermal.c,
  processor_thermal_device.c, kirkwood_thermal.c and exynos_tmu.c
- Add better description for set_trips callback
- update the interrupt triggers also when the trip points change
- Add missing MODULE_* tags
- Broaden temperature range in the Mediatek driver so that we can be sure
  the measured temperatures are really out of the desired range

Changes since v2:
- Add Mediatek thermal controller driver as first user for hardware trip
  points

Changes since v1:
- Use int instead of unsigned long consistently for temperatures
- Instead of misfixing the emulation code add a comment how the
  code is meant
- Add doc entry for .set_trips callback
- initialize prev_low_trip/prev_high_trip properly
- get tz->lock before calling thermal_zone_set_trips()