power_supply: Add CHARGE_COUNTER_SHADOW property to power supply

Add the "CHARGE_COUNTER_SHADOW" property to the power supply
framework that signifies a shadow charge counter of the power supply.
This should be a shadowed version of the charge counter that is not
cleared automatically.
The units for this property should be in microamp-hours.

Change-Id: Ia9504a3c36af305e42d0503cf791594449249fa0
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>
diff --git a/drivers/power/power_supply_sysfs.c b/drivers/power/power_supply_sysfs.c
index 5cdb666..11e6cc1 100644
--- a/drivers/power/power_supply_sysfs.c
+++ b/drivers/power/power_supply_sysfs.c
@@ -159,6 +159,7 @@
 	POWER_SUPPLY_ATTR(charge_now),
 	POWER_SUPPLY_ATTR(charge_avg),
 	POWER_SUPPLY_ATTR(charge_counter),
+	POWER_SUPPLY_ATTR(charge_counter_shadow),
 	POWER_SUPPLY_ATTR(energy_full_design),
 	POWER_SUPPLY_ATTR(energy_empty_design),
 	POWER_SUPPLY_ATTR(energy_full),