power: qpnp-smbcharger: support reading temperature and current

Currently, POWER_SUPPLY_PROP_TEMP and POWER_SUPPLY_PROP_CURRENT_NOW are
only exported by the bms power supply because they are provided by the
fuel gauge peripheral. However, android looks for temperature and
current under /sys/class/power_supply/battery/, which currently does not
support reading the temperature and current.

Fix this by exporting these properties in the battery power supply as
well, by making them read through to the bms power supply.

CRs-Fixed: 712920
Change-Id: I8832ae3ae5f0294efac08d7424e3a49233fa6a52
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>