power: smb5: add support to configure charger temp_max

Currently, both PM8150B and SMB1355 charger temp_max settings come
from their die REG_H_THRESHOLDs. Add additional support to read the
property from device tree, which take precedence if exists.

Change-Id: I78b4376adb62bf6c95b4b128817e03db22d827f1
Signed-off-by: Harry Yang <harryy@codeaurora.org>