ACPI: battery: add sysfs serial number

egrep serial /proc/acpi/battery/BAT0/info
serial number:           32090

serial number can tell you from the imminent danger
of beeing set on fire.

Signed-off-by: maximilian attems <max@stro.at>
Acked-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index c4a769d..f6215e8 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -194,6 +194,9 @@
 	case POWER_SUPPLY_PROP_MANUFACTURER:
 		val->strval = battery->oem_info;
 		break;
+	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
+		val->strval = battery->serial_number;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -212,6 +215,7 @@
 	POWER_SUPPLY_PROP_CHARGE_NOW,
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,
+	POWER_SUPPLY_PROP_SERIAL_NUMBER,
 };
 
 static enum power_supply_property energy_battery_props[] = {
@@ -226,6 +230,7 @@
 	POWER_SUPPLY_PROP_ENERGY_NOW,
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,
+	POWER_SUPPLY_PROP_SERIAL_NUMBER,
 };
 #endif