drivers: thermal: bcl: Add BCL peripheral driver

Add snapshot of BCL driver from kernel 4.9 as of 'commit
<a6431e8beca> ("drivers: thermal: bcl: Update vbat vlow and clow trip
threshold logic")'.

Change-Id: I903fdec14b1657e3da762e254de6a391ef8e630a
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>