FROMGIT: power: supply: sc27xx: Add POWER_SUPPLY_PROP_CHARGE_NOW attribute

Add the POWER_SUPPLY_PROP_CHARGE_NOW attribute to allow user to get
current battery capacity (uAh) to do measurement.

bug: 146864653
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
(cherry picked from commit 1c5dfc5e3f2df5892a849621d729daa87cfef436
https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git for-next)