ieee802154/atusb: Mark driver as AACK enabled in hardware.

Since firmware version 0.2 we use AACK handling directly in the firmware.
Inform the stack that the hardware supports and uses it.
Signed-off-by: NStefan Schmidt <stefan@osg.samsung.com>
Acked-by: NAlexander Aring <alex.aring@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

drivers/net/ieee802154/atusb.c

@@ -568,7 +568,8 @@ static int atusb_probe(struct usb_interface *interface,
 		goto fail;
 
 	hw->parent = &usb_dev->dev;
-	hw->flags = IEEE802154_HW_TX_OMIT_CKSUM | IEEE802154_HW_AFILT;
+	hw->flags = IEEE802154_HW_TX_OMIT_CKSUM | IEEE802154_HW_AFILT |
+		    IEEE802154_HW_AACK;
 
 	hw->phy->current_page = 0;
 	hw->phy->current_channel = 11;	/* reset default */