drivers: thermal: bcl_soc: Add Battery state of charge driver

Add Battery state of charge driver, which will register the battery
state of charge as a sensor with thermal framework. This driver can take
a low threshold to monitor and will notify the thermal framework when
the state of charge goes below the threshold.

Change-Id: Ia553c49f7588dccf077d2b69e3061b609876f79c
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>