qtnfmac: drop nonexistent function declaration

Function qtnf_classify_skb_no_mbss has been used for debug
during early stage of development. Drop its declaration.
Signed-off-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/quantenna/qtnfmac/core.h

@@ -153,9 +153,6 @@ int qtnf_cmd_send_get_phy_params(struct qtnf_wmac *mac);
 
 struct qtnf_wmac *qtnf_core_get_mac(const struct qtnf_bus *bus, u8 macid);
 struct net_device *qtnf_classify_skb(struct qtnf_bus *bus, struct sk_buff *skb);
-struct net_device *qtnf_classify_skb_no_mbss(struct qtnf_bus *bus,
-					     struct sk_buff *skb);
-
 void qtnf_virtual_intf_cleanup(struct net_device *ndev);
 
 void qtnf_netdev_updown(struct net_device *ndev, bool up);