HID: wacom: generic: Report AES battery information

When support for the HID_DG_BATTERYSTRENGTH usage was added for AES devices,
it appears that the value was read, but never actually forwarded to the
power_supply subystem for userspace's benefit. Let's correct that.

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom_wac.c

@@ -2177,6 +2177,8 @@ static void wacom_wac_pen_report(struct hid_device *hdev,
 		input_sync(input);
 	}
 
+	wacom_wac_pad_battery_report(hdev, report);
+
 	if (!prox) {
 		wacom_wac->tool[0] = 0;
 		wacom_wac->id[0] = 0;