wl12xx: add hw configuration for max supported AMDPU size

The wl12xx chips do the AMDPU aggregation work in the firmware, but it
supports a maximum of 8 frames per block.  Configure the mac80211 hw
structure accordingly.
Signed-off-by: Luciano Coelho <coelho@ti.com>
Tested-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>

drivers/net/wireless/wl12xx/main.c

@@ -3180,6 +3180,8 @@ int wl1271_init_ieee80211(struct wl1271 *wl)
 
 	wl->hw->sta_data_size = sizeof(struct wl1271_station);
 
+	wl->hw->max_rx_aggregation_subframes = 8;
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(wl1271_init_ieee80211);