ANDROID: GKI: power: supply: Add POWER_SUPPLY_PROP_VOLTAGE_FIFO

Partially taken from commit e2ad4f0b2c946a0582cb5c3a41ab3a50224c6b73
("qpnp-qg: calculate Vbat FIFO averages for FVSS scaling")

Signed-off-by: Jack Wu <wjack@google.com>
Bug: 141451339
(cherry picked from commit e2ad4f0b2c946a0582cb5c3a41ab3a50224c6b73)
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Bug: 150789066
Change-Id: Id6da95c93322bd3c84f6450fad4bfa2d50a9c2ce

drivers/power/supply/power_supply_sysfs.c

@@ -473,6 +473,7 @@ static struct device_attribute power_supply_attrs[] = {
 	POWER_SUPPLY_ATTR(charge_disable),
 	POWER_SUPPLY_ATTR(adapter_details),
 	POWER_SUPPLY_ATTR(dead_battery),
+	POWER_SUPPLY_ATTR(voltage_fifo),
 	/* Capacity Estimation */
 	POWER_SUPPLY_ATTR(batt_ce_ctrl),
 	POWER_SUPPLY_ATTR(batt_ce_full),

include/linux/power_supply.h

@@ -338,6 +338,7 @@ enum power_supply_property {
 	POWER_SUPPLY_PROP_CHARGE_DISABLE,
 	POWER_SUPPLY_PROP_ADAPTER_DETAILS,
 	POWER_SUPPLY_PROP_DEAD_BATTERY,
+	POWER_SUPPLY_PROP_VOLTAGE_FIFO,
 	/* Capacity Estimation */
 	POWER_SUPPLY_PROP_BATT_CE_CTRL,
 	POWER_SUPPLY_PROP_CHARGE_FULL_ESTIMATE,