DCB: Add interface to query # of TCs supported by device

Adds interface for Data Center Bridging (DCB) to query (and set if
supported) the number of traffic classes currently supported by the
device for the two (DCB) features: priority groups (PG) and priority
flow control (PFC).

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/dcbnl.h b/include/net/dcbnl.h
index 183ed04..f0a6528 100644
--- a/include/net/dcbnl.h
+++ b/include/net/dcbnl.h
@@ -40,6 +40,8 @@
 	void (*getpfccfg)(struct net_device *, int, u8 *);
 	u8   (*setall)(struct net_device *);
 	u8   (*getcap)(struct net_device *, int, u8 *);
+	u8   (*getnumtcs)(struct net_device *, int, u8 *);
+	u8   (*setnumtcs)(struct net_device *, int, u8);
 };
 
 #endif /* __NET_DCBNL_H__ */