hwmon: qpnp-adc-voltage: Add temperature compensation

Add VBAT and OCV temperature compensation for PM8916
v1.1 and v2.0. The temperature compensation is required
on top of gain/offset calibration to compensate for
variations due to chip revision, manufacturer and
temperature.

Change-Id: I0a9b65d8e4f7ce88c554558355518740dceb91fb
Signed-off-by: Dipen Parmar <dipenp@codeaurora.org>