hwmon: qpnp-adc-voltage: Modify temperature compensation

Apply temperature compensation to minimum(die_temp, 60degC)
for vbatt compensation. For OCV temperature compensation
apply the compensation based on the die_temp for the
corresponding PMIC. The temperature compensation is
required on top of gain/offset calibration to compensate
for variations due to chip revision, manufacturer and
temperature.

Change-Id: I0826993ddebe7dae2f033d995fa1266f9509002c
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>