thermal: tsens: Add 8974 TSENS driver

MSM8974 TSENS block supports 11 temperature
sensors that are used for thermal mitigation.

The TSENS driver is part of the thermal sysfs
framework that allows clients to set thresholds
and receive notification on temperature thresholds
being crossed through thermal sysfs.

The driver provides ability to thermal clients
to set upper/lower thresholds for each sensor
and receive individual notification for each
sensor once the threshold is crossed.

All sensors are enabled by default during
driver initialization.

The driver is initialized early during kernel
initialization to provide capability to the
thermal kernel driver to read temperature
from the TSENS sensors. To support this feature
a kernel API is provide to read the TSENS
temperature.

Change-Id: If17daae81cfb522a9cea786b5db0c920adb5ed2d
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>