ARM: dts: msm: Add support for bat_therm for PMI632 on trinket

Add support for bat_therm, to ensure correct scaling function is
selected, for bat_therm on Nebula on trinket.

Change-Id: Ib6b39dc9d11fe4a123dbc46e623a12c97593ab4a
Signed-off-by: Jishnu Prakash <jprakash@codeaurora.org>