thermal: read thermistor temp from sysfs

- avoid wrong sensor value reading for thermalHAL

Bug: 327327502
Test: Build to boot to home
Flag: EXEMPT (bug 337358613)
Change-Id: I342bcbfb5ee884aa437d4d4552aeea7d0a9df119
Signed-off-by: Peter (YM) <[email protected]>
4 files changed