ARM: dts: msm: Remove VADC and BTM thermistor channels for PM8941

MSM8974 PRO AC device uses PMA8084 and PM8941. On
PM8941 thermistors are not connected to any channels.
Removing these channels will avoid reading incorrect
values.

Change-Id: I048cddfc023cfca28dbe635831059ac812efe069
Signed-off-by: Dipen Parmar <dipenp@codeaurora.org>