sfc: Enable a VF to get its own MAC address

A VF's MAC address is set by its parent PF and added to its vport.
To get this MAC address, the VF must use MC_CMD_ VPORT_GET_MAC_ADDRESSES.
In the current scheme, a VF's vport should only have one MAC address,
so warn if this is not the case.

Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index f6c4832..364217b 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -1351,6 +1351,7 @@
 	int (*vswitching_probe)(struct efx_nic *efx);
 	int (*vswitching_restore)(struct efx_nic *efx);
 	void (*vswitching_remove)(struct efx_nic *efx);
+	int (*get_mac_address)(struct efx_nic *efx, unsigned char *perm_addr);
 
 	int revision;
 	unsigned int txd_ptr_tbl_base;